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Chapter 4 The Effects of Chemical Reactions. • Introduction to Chemical Reactions. - Chemical reaction: a process in which one or more substances change into one or more new substances. - Clues that a chemical reaction has occurred : 1. Color change Example: two colorless aqueous solutions mix together to produce a bright yellow precipitate. 2. A precipitate (solid) is formed when mixing two solutions together. 3. Gas formation. Bubbles of gas (effervescence) are produced when mixing substances together (solid – liquid or aqueous – aqueous ….) 4. Heat is produced. - Chemical reactions are described by using word equations or chemical equations. - Chemical equations need to be balanced when written because it shows the correct proportions (amounts) of chemicals in a reaction. - A balanced chemical equation has equal number of atoms of each element in the reactants (left hand side) and the products (right hand side). - Exercise: Balance the following equations. a) KClO3→KCl + O2 b) Na2O + H2O NaOH c) Cu + AgNO3 Cu(NO3)2 + Ag d) C3H7OH + O2 CO2 + H2O • Synthesis and Decomposition Reactions. Synthesis: Two or more substances (elements and / or compounds) combine to form one larger compound. General pattern: A + B → C Examples: N2 + 3 H2 → 2 NH3 CaO + CO2 → CaCO3 2 P + 3 Cl2 → 2 PCl3 Decomposition: This is opposite to synthesis; that is, one large compound breaks down (decomposes) into 2 or more simpler substances. Example: 2 KClO3 → 2 KCl + 3 O2 General pattern: R → S + T Remark: Usually decomposition happens due to heat or electricity. - Predicting the product of decomposition or synthesis reactions. 2 AlCl3 (s) → 2 Al (s) + 3 Cl2 (g) Zn (s) + S (s) → ZnS (s) 2 Zn (s) + O2 (g) → 2 ZnO(s) - Single Displacement (Replacement) Reactions. Definition: A reaction in which an element displaces (replaces) another element in a compound, producing a new compound and a new element. General pattern: A + BC → AC + B Example: Mg (s) + CuSO4 (aq) → MgSO4 (aq) + Cu (s) Zn (s) + 2 AgNO3 (aq) → Zn(NO3)2 (aq) + 2 Ag (s) Fe (s) + MgCl2 (aq) → no reaction. Remark: The element that displaces the other element in a compound must be more reactive (active) than that element, otherwise no reaction takes place. In the general pattern above, A should be more reactive than B for the reaction to proceed. The following reactivity (activity) series lists the chemical strength (reactivity) of the metals in order from the more reactive to the less reactive. KPlease stop calling my amazing zebra in the long Nahungry class. sorry !! Ca Mg Al Zn Fe Sn Pb H Cu Ag Examples of single displacement reactions : 2 Al (s) + 3 CuSO4 (aq) → Al2(SO4)3 (aq) + 3 Cu (s) Sn (s) + Zn(NO3)2 (aq) → no reaction Exercise: Complete and balance the following equations. If there is no reaction occurring write no reaction. a) 2 Al (s) + 6 HCl (aq) → 2 AlCl3 (aq) + 3 H2 (g) b) Cu (s) + H2SO4 (aq) → no reaction c) 2 AlCl3 (aq) + 3 Ca (s) → 3 CaCl2 (aq) + 2 Al (s) d) Mg (s) + 2 HNO3 (aq) → Mg(NO3)2 (aq) + H2(g) - Reactivity of halogens decreases down the group. F2> Cl2> Br2> I2 The reactions taking place for the halogens or their compounds are in solution (aqueous) Examples: Cl2 (aq) + 2 KBr (aq) → 2 KCl (aq) + Br2 (l) Cl2 (aq) + NaF (aq) → no reaction. Exercise: F2 (aq) + 2 LiCl (aq) → 2 LiF (aq) + Cl2 (g) I2 (aq) + NaCl (aq) → no reaction • Double displacement reactions. - Definition: A reaction in which two compounds mix together and an exchange of ions (elements) occurs which results in the formation of 2 new compounds. - General pattern: AB + CD → AD + CB - Solubility: the amount of solute that dissolves in a given amount of solvent at a given temperature. - When we say a substance is soluble, it means it dissolves in water; whereas if it is insoluble it means it doesn’t dissolve in water. - The compound in a reaction that is soluble is in aqueous (aq) phase, whereas the compound which is insoluble is in the solid state (s). - The solid which is formed in a double displacement reaction is called the precipitate and it is insoluble. - Solubility rules (used in double displacement reactions). 1. All alkali metal ions and ammonium ion (NH4+) are soluble. 2. All nitrates (NO3-) are soluble. 3. All sulfates (SO4-2) are solubleexceptwith Ba+2 , Pb+2 , Ca+2 , Sr+2 , Ag+ . 4. All chlorides, bromides and iodides(Cl-, Br-, I-) aresolubleexcept with Ag+ , Pb+2 , Hg+, Cu+ 5. All OH- are insolubleexceptwith rule 1, and Ba+2 and Sr+2 . 6. All oxides (O2-), sulfides (S2-), sulfites (SO32-), carbonates (CO32-), phosphates (PO43-) are insoluble except with rule 1 Remark: If all compounds formed in a double displacement reaction are soluble (aqueous) then no reaction takes place. Exercise: State whether each of the following compounds is soluble or insoluble ? Na2SO4 : Fe(NO3)2: LiOH: ZnSO4: PbBr2: BaSO4: Mg(OH)2: PbO: NH4Cl: Na2S: Cu(OH)2: KF: Exercise: Complete and balance the following chemical equations: - KNO3 (aq) + NaCl (aq) → - LiCl (aq) + AgNO3 (aq) → - Zn (s) + FeSO4 (aq) → - NaOH (aq) + CuCl2 (aq) → - ZnCl2 (aq) + Na3PO4 (aq) → - Pb(NO3)2 (aq) + K2S (aq) → • Net ionic equation: a chemical equation which shows ONLY the ions that are involved in the formation of the precipitate (solid). Examples: Pb+2 (aq) + S-2 (aq) → PbS (s) Ag+ (aq) + Cl- (aq) → AgCl (s) Cu+2 (aq) + 2 OH- (aq) → Cu(OH)2 (s) • Full ionic equation: an equation which shows All the ions in the soluble (aqueous compounds) in both reactants and products. Example: - 2 NaOH (aq) + CuCl2 (aq) → 2 NaCl (aq) + Cu(OH)2 (s) 2 Na+ (aq) + 2 OH- (aq) + Cu+2 (aq) + 2 Cl- (aq) → 2 Na+ (aq) + 2 Cl- (aq) + Cu(OH)2 (s) - 3 ZnCl2 (aq) + 2 Na3PO4 (aq) → Zn3(PO4)2 (s) + 6 NaCl (aq) Full ionicequation: 3 Zn+2(aq) + 6 Cl-(aq) + 6 Na+ (aq) + 2 PO4-3 (aq) → Zn3(PO4)2 (s) + 6 Na+ (aq) + 6 Cl- (aq) Net ionic equation: 3 Zn+2 (aq) + 2 PO4-3 (aq) → Zn3(PO4)2 (s) Exercise: Complete and balance the following equation, then write full ionic and net ionic equations for the reaction. Pb(NO3)2 (aq) + 2 NaI (aq) → Full ionic equation: Net ionic equation: Spectator ions: the ions that are not involved in the formation of the precipitate (solid). Note that the spectator ions appear on both sides of the full ionic equation. For example, in the above reaction, Na+ (sodium ions) and NO3- (nitrate ions) are the spectator ions. Exercise: Complete and balance the following equation, then write the net ionic equation and identify the spectator ions. BaCl2 (aq) + K2SO4 (aq) → Net ionic equation: Ba+2 (aq) + SO4-2 (aq) → Spectator ions: - Combustion reaction is a special type of (synthesis) reaction in which the substance reacts with (burns in) oxygen. Examples: C(s) + O2(g) → CO2(g) • Production of gases (lab scale): 1. CO2 2. SO2 3. H2 4. H2S (hydrogen sulfide) 5. NH3 (ammonia) General pattern of the chemical reactions to produce the above gases: 1. Metal carbonate + acid → CO2 Example: Na2CO3 (aq) + 2 HCl (aq) → 2 NaCl(aq) + CO2(g) + H2O(l) 2. Metal sulfite + acid → SO2 K2SO3 (aq) + 2 HCl (aq) → 2 KCl(aq) + SO2(g) + H2O(l) 3. Metal + acid → H2 Remark: This is a single displacement reaction therefore the metal used in the reaction should be higher in the reactivity series than hydrogen. Zn (s) + 2 HCl (aq) → ZnCl2 (aq) + H2(g) 4. Metal sulfide + acid → H2S Na2S (aq) + 2 HCl (aq) → 2 NaCl (aq) + H2S (g) 5. Ammonium compound + base (alkaline solution) → NH3 NH4Cl (aq) + NaOH (aq) → NaCl (aq) + NH3 (g) + H2O (l) Exercise: Write the net ionic equations for each of the above 5 reactions. Answers 1. 2 H+ (aq) + CO3-2(aq) → CO2(g) + H2O (l) 2. 2 H+ (aq) + SO3-2(aq) → SO2(g) + H2O (l) 3. Zn(s) + 2 H+(aq) → Zn+2(aq) + H2(g) 4. 2H+ (aq) + S-2 (aq) → H2S (g)
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Sports & Exercise Science Lectures History of Sport and Exercise Science, highlighting relevance of training principles today. • Historian part of speaker finds interest in history of Sport and Exercise Science. Sport and exercise science history and its evolution. • Sport Science: Systematic approach to understanding factors relating to sports performance. • Exercise Science: Systematic approach to understanding how the human body responds to physical activity. • Agriculture led to sedentary lifestyle and exercise became a way to combat it (0:03:14) • Ancient Chinese philosophers like Confucius and Hippocrates advocated for exercise as a means of maintaining health (5000 years ago) Exercise science history, including Leonardo da Vinci's anatomical sketches and early physiology experiments. • Leonardo da Vinci (1500s) made accurate anatomical sketches, discovering heart as muscle pump and nervous system hierarchy. • William Harvey (1600s) discovered blood circulation in one direction, and Boyle (1600s) found Boyle's law, which explains breathing mechanism. • Johan Bernoulli (1700s) developed mathematical models to explain muscle mechanics, using tractors to investigate muscle contractions. • James Lin discovered the origins of scourgia by inviting vitamin C-rich food, with great success. • Anton Laviesia named oxygen and recognized hydrogen as an element, and his experiments on human respiration led to a better understanding of metabolism and nutrition. Note Sport and Exercise Science sub-disciplines and their roles in sport and clinical contexts. • Sport and Exercise Science sub disciplines explore roles in sporting and clinical contexts (psychologists, biomechanics, nutritionists, strength coaches, physiologists, performance analysts) • Accredited Exercise Physiologists provide individualized exercise programs for high-risk populations (hypertension, heart disease, diabetes, musculoskeletal conditions, injuries) Exercise physiology and biomechanics in sports. • Exercise physiologist specializes in prescribing exercise for patients with chronic diseases or injuries. • Sports physiologist studies the physiological demands of sports and advises athletes on training and competition. • Biochemist analyzes technique and injury mechanisms in sports, measuring mechanical loads and risk assessments. Improving athletic performance through strength training and conditioning. • Unknown Speaker discusses biomechanics and jumping throws, using a three-mesh Castle system to measure angles, velocities, and selections of throwing motion. • Strength and conditioning coach works with athletes to improve strength, power, speed, fitness, acceleration, agility, endurance, and flexibility. • Coach designs programs to reduce injury risk, optimize recovery, and deliver rehab programs in conjunction with medical staff for injured athletes. Motor control, learning, and performance in sports. • Motor control specialists focus on learning, performing, and retaining motor skills over time. • Sport psychologists help athletes overcome barriers to optimal performance, using techniques like visualization and mindfulness. Sports dietitians' role in optimizing athletes' health, performance, and nutrition. • Sports dietitians tailor nutritional strategies for athletes to optimize health, performance, and body composition. • Dietitians recommend food first approach and supplements when necessary, and provide individualized advice and hydration stations. • Unknown Speaker discusses six specialist supplements in Sport and Exercise Science, including nutrition (12:30) • Speaker shares insights on interdisciplinary approach to high performance in surfing, with focus on strength conditioning and sport science (14:45) Functional Anatomy an understanding of how to use a correct terms to describe movement interaction, understand major bones, muscles, joints, and how they work together in human movement, and begin to develop the ability to form a movement. Analysis of exercise and supporting tasks. Despite in this lecture, if you're unfamiliar with anatomy, it might require a second viewing. Beautiful lecture is the ability to stop review. If you require any further help with the content, please reach out to your tutor. So the first thing I understand in anthropical language is that whenever we refer to position or something, we're referring to it in its position when in the anatomical position. So this is the standardized position of the body where it is always direct and facing forwards, with the palms of the side of the body, toes and palms of the hands facing forwards. Having a standard anatomical position is crucial to reference and describe the relationship of body sequence to one another when it is anatomical position. There are three COVID plans from which we can view or segment the body that is essential, frontal and reverse plastics. So the station plane, or the median plane, is the side on view of the body, meaning you see a profile of the person. The frontal plane is also called the corona plane, and there's the view we get between directly at the front or back of the body. And finally, the transverse plane, also called the horizontal plane, is the birds of view of the body. There generally can be from the ground up as well, right, if it's never nearly achieved. And the other understand that the body can be viewed in three different planes. It's relatively straightforward to understand that rotational movement also occurs in each of these three axes. So this is called an axis of rotation, and is essentially an imaginary line about which any rotational movement occurs perpendicular to that Cardinal plane of action, just like the anatomical position and Cardinal planes allow us to describe the relative positions with different body parts. So it doesn't understand axis of rotation allows us to constantly describe human movement. However, most movements of human body typically occur about two or more axes of rotation, which makes the analysis of human movement far more challenging. So you think about the 3x Y and Z plane take elbow flexion like a bicycle. When view from front and the front plane, it looks like the forearm hand is simply moving up towards the face, open, viewed side on from the sagittal plane, you see that the forearm hand also moving away from the body and then back towards the body as it goes through that arc. Movement. This way to understand all three other anatomical positions, the counter planes and the axes of rotation, to be able to accurately describe pure movement. So now we can consider best view in his plans. So in the anatomical position, the most common actually the rotation between the SAP flexion and extension. And we'll go through that few slides for now. Include flexion and extension at the wrist, elbow, shoulder, neck, trunk, hip, knee and ankle. At the ankle. It's also referred to as dorsi flexion and plantar flexion, rather than flexion extension. Multi joint actions can involve both. So kicking your foot forwards involve flexing the hip, swinging forward and extending in the knee. Some of that actually rotation. Best views in the frontal plane include adduction and abduction at the shoulder and hip, lateral flexion at the neck and trunk, as well as radial and ulna deviation at the wrist and diversion and inversion at the ankle. And this is why I move the mechanism, which can result in raw ego the arm actually in breast stroke. Swing is adduction, kicking a stop or the ring forward involved adduction of the hip. Two legs coming together are being added so that's adduction. When the arm is being taken away from the body, it is being abducted. It's been taken away. Finding the transverse plane. Some of the best view axes of rotation and movements include internal and external rotation of the shoulder and hip, and horizontal adduction and abduction for the shoulder and the forearms, pronation and supination and neck and trunk rotation. Each of these three slides are diagrams. Highlight the movements just went through. The next slide go through the names of these moves and what the actions are. Flexion and extension refer to increasing and decreasing the angle in the frontal plane. So for instance, elbow flexion is raising your forearm and hand, while extension is lowering back down. This is truthfully all flexion extension, except for the ankle, which you remember dorsiflexion and plantar flexion. So dorsiflexion refers to moving the top of the foot towards the leg, and plant deflection is away from the leg towards the ground. I find this easier to remember using your plan to flexion as the movement required to step on a plane with your toes. Adduction. And adduction refer to moving away or towards the central plane. Next is protraction and retraction. This is moving something forward or patterns. And a good example is the second level of shoulder blades. When you pull your shoulder blades back and away. This is attraction. Protraction is the opposite elevation and depression. Can be also thought of with regarding the shoulder is raising, like in a shrug, while depression is lowering back down another shoulder blade sample is upward and downward rotation, with upward rotation referring to the rotational movement around access to a point superior and downward rotation, maybe opposite. Medium and lateral rotation referred to rotating toward or away from midnight. So the arms hanging medial rotation is internal rotation of your arm, the shoulder towards midnight, and external or lateral rotation being back away from midnight. Pronation suppression has special terms for forearm movement. With a forearm rotation to have your palm facing upward in an anatomical position in front of supreme and the back of your hands facing forward into pronation. We can also use these terms of the foot, but they are known as inversion, meaning the sole of the foot faces towards mid level E version, when the solar foot rolls away from the middle. Our last two terms, especially with the circumduction, referring to the combination of flexion and attention abduction and medial lateral rotations, and often we could curtain rally, but when we move up arms or legs, it's usually not in a single plane through a multiple plane with multiple positive move and social conduction despises. Now opposition is the movement of bringing tips of your fingers and thumb together. And the reason we also have possible thumbs are very useful with lasers pick up items. Here is a diagram illustrating protraction, retraction, elevation and depression, these lines of upper rotation and downward rotation. So on this slide is a consolidated view of some special actions that only currently in places. So we've got scapular to demonstrate protraction, retraction, depression, elevation, plus upward and downward rotation. You can see that you can invert or divert the ankle. In running terms, we can talk about pronation as collapsing inwards during foot strike, which means I saw the foot faces away from midline. Next is illustrate example of plantar flexion and dorsiflexion and ankle, and define this example of protraction, retraction, elation and depression of the Mandal which is the lower jaw bone. So you would think that with each member of the move toward or away from the midline, or up versus down, all these things, or have anatomical terms to solve the time in terms of the direction of body. So anterior and posterior refer to the front and back of the body in atomic position. You also call them ventral end dorsal, and think of dorsalism, but the dorsal is the dorsal fin on the back, mostly we refer to as anterior and posterior. Superior and inferior refer to the directions towards the head or towards the feet, while medial and lateral refer to the direction towards the midline or away from midline in a sideways direction, approximately distal, our special tendencies to refer to the relative positioning of something compared to another landmark. So if something is distal, it refers to sides located away from a specific area, most often the center of body, and for instance, the hand is visible to the elbow. Proximal refers to sites located towards a specific area, so the COVID The elbow is proximal to the hand. The term distal, or is maximum or distance or proximal indicates proximity. Now last terms are superficial and deep, which require you to think in three days. So something that's superficial is close to the surface or the skin of the body, or something that's deep is away from so muscles are deep to the skin, but superficial to bone. So many of these will become important when we talk about anatomy, as certain structures can be proximal or anterior or superficial to other structures. The human anatomy is built around the scaffolding of the split system. So this slide shows you in the structure an anatom. We're not going to go through that in this lecture for this electron. Functional anatomy is more important than understand the function of the skeleton that bones make up, beyond just being the strong structure holding us together, the way the bones fit together and serve as attachment points for the ligaments, tendons and muscles, serves to allow various movements of the body that we've already discussed. The skeleton by the rib cage also protects wild organs, while the internal structure of the bone allows for the storage of minerals and production of new blood cells. We wouldn't have any of the functional movements we've discussed so far without having a skeleton to support these movements. There are 206, bones in the human body. We don't need to learn them all, but we're certainly discussing some of them in this unit. So basic understanding of the major structure of the skeleton is important, and you can use this as a reference for some of those major bones. In this particular image, the green bones represent the actual skeleton, and the non green turn the perpendicular skeleton thanks to better understand how movement can occur in the body. Is cartilage, which is a stiff but flexible connective tissue found in many applications throughout the body. So cartilage is composed of specialized cells called corona sites. They produce a large amount of extracellular matrix. So cartilage can be classified as three types. We have hyaline cartilage, which forms a smooth surface on articular joint surfaces, with Fibro cartilage that is a part of form of cartilage found at sites such as the pubic symphysis. And you've got elastin cartilage, which can be found in here. Cartilage doesn't actually contain blood vessels instead, the chondrocytes are supplied by diffusion, which is helped by the pumping action generated by the compression of articulate cartilage or flexion of the elastic charge. So because it doesn't have a blood supply, cartilage grows and repairs more slowly, which is why cartilage injuries are so slow to healing athletes and and often require arthroscopic surgery, which are inelastic but flexible bands of connective tissue that attached, attached two bones together so they enhance joint stability by maintaining the alignment of bones and limiting range of motion. Those are the two primary functions keep bone and enhancement stability. The most common injuries involve involving into sprains, which means over stretching and tearing of the fibers, and they can be quite slow to heal. So if we bring that together, we get a joints so these facilitate the movers that we discussed at the front of this lecture, per muscular structure, joined by the ones, separate by cartilage. The form joints, which used to be also called articulations. There are three types of classifications of joint. So we have fibrous joints, which are bound by dense connective tissue. And these are joints in the scale, and they really don't move much. You have a catalyst joint, which, as the name suggests, is a joint with fibrous cartilage separating two bones, such as the symphysis, pubis and the ribs. And again, they don't move very much. And then finally, we have synovial joints, which are bound by a joint capsule in containing ligaments and muscles to allow them to occur. And these are the ones with most interesting in this lecture. So not only a synovial joints most interesting for me, but also the most common type of joint. So the articulate capsule, which surrounds synovial joint forms a kind of SAC around the joint. And so there's also synovial membrane inside the articulate capsule, which secretes synovial fluid, and this lubricates the articular cartilage of the joint services, similar to enjoy car lubricating the moving parts. It also nourishes the joint structure, and it can act as a shock absorber, distributing the stress evenly across the articular surface. So all of this combines to allow for smooth fluid movement joints, and usually without needing an oil change during your lifetime, as we've already gone over, the bones with the joints are held together by ligaments. But what we haven't talked about here is the joints can also contain something else called a bursa, which we'll discuss a bit later. So even though synovial joints are major type of joint, they can also be classified with various types of synovial joints. So we have plain joints, which can be found in the joints between the vertebral articulating surfaces. We've got hinge joints such as the elbow or the knee. We have pivot joints such as the ulnar and radius. We have COVID joints in the fingers. We have several joints, which is the thumbnail and sub joint, such as the hip and joint. Okay, so this is a very useful slide for a reference for various locations where these joints can be found. As I mentioned before, we have bursa which can sometimes occur with some synovial joints. These are small sacks of fibrous tissue filled with synovial fluid, and they are found where different parts move over one another in the body, and they help reduce friction within the joint. So these mostly occur with bones, ligaments, muscles, skin or tendons, over later, and will rub together. If a person comes in flames, it can lead to an injury you might have heard for bursitis, where the bursar releases too much fluid and the joint gets very swollen, and they can make movement difficult. So burst sit around tendons, and so that's the next structure that we look at. So tendons are tough but flexible bands of tissue that attach muscle to bone and help facilitate movement. So like many fibrous structures we've already discussed, they have a limited blood supply, which makes healing and repair slow. Some common tenderness injuries, which are strains or over stretching. Can be a tenderpathy or tenderloin, which is a result of inflammation, and tenderlois, which is a chronic inflammatory condition. Lastly, we have the muscles, and as with the bones, you'll do need to understand some of the basic muscles of the body, but for the for this functional anatomy component, we'll just talk about the functions of the skeleton worker. So essentially, our muscles control our posture. They provide support for the soft tissues in the body. They allow the body to store energy to use during movement exercise. They can guard entrances and agents in the body, and they also produce heat to allow us to regulate our body temperature. When muscle is contracted, it pulls on the tendon of the muscle, which in turn is connected to the bones, bone, and then we get the movement. So the way in which that occurs in a single muscle cell fiber is made up of many myofibrils, which can make up any starters. So within the start of me there's actin and myosin filaments, and that's called an actin mycin cross bridge. And they slide past and pull each other closer together or further to control the movement. So whilst we're over the 700 muscles in the body, here's a list of some of the major muscles that we'll refer to, and you'll cover it in a different unit, but certainly will be exposed as many of these throughout the labs. So reaching the end of this lecture, we now have to use the knowledge from this lecture to answer some applied problems. So during stationary cycling, what plane or planes of movement is this exercise occurring? So what axis of rotation is movement occurring? So we will need to look at a sporting movement or an exercise and describe it in its proper anatomical terms, so not always as simple as stationary cycling. So take this diagonal Wood Chop exercise as an example. This is still quite a basic movement. If there are multiple axes of rotation occurring through multiple planes involving many joints, bones and muscles. And even in a more complex example, we can go to Goldsmith and see movement across multiple axes of rotation of all three planes. For example, the frontal plane, we can see abduction and abduction, as well as inversion and inversion. In the Sagitta plane, we can see flexion and extension in the medial lateral axis. On the transverse plane, we can see rotation around the longitudinal latches. Many real world supporting movements will be like this, involving a complex coordination of many movements across many planes. We will work through all of these in the labs. So to be able to describe all of these different actions using proper environmental terminology, I highly recommend you start the voting time to study with most of your three credit point units. You'll find that towns a week is allocated for full time state, only four hours of that is lectures and labs, which leaves the rest of your time for state. So please use that time, why is it, this particular left of today on functionality, you may have many questions about plans of movement anatomical terms. I'm trying to write them down, bring them to the lab so that we can speak to your tuners about their experiences with learning this material. Thanks for watching this lecture. Body compostion In this lecture, we will cover body composition, the different types of tissue in the human body, and how these are distributed, measured and the impact on our health. of this lecture, you'll have an understanding of the components of body composition and implications of body composition on health. So body composition is the general term that refers to the relative amounts of tissue types of the body, generally related to fat and fat free mass. It is expressed as a percentage of body fat. There are general classifications of body composition, from underweight to severely obese. Body Composition is related to general health and can also have an impact on supporting performance. The assessment of body composition can be used to monitor lifestyle interventions. There are optimal ranges for health and exercise. Professionals administer different Exercise and Nutritional strategies to influence body composition. There any correlations between risk of chronic disease and body position, including coronary heart disease, diabetes, hypertension, some cancers, hyperlipidemia is more commonly referred to as high cholesterol, but encompasses several blood lipids. Body Mass Index is one measure of obesity as a relationship between height and weight. On this low we can see the relative risk of type two diabetes starts increasing rapidly between BMI 25 to 30, which is Catia crisis, overweight, and beyond, which is obese. We can see on the right side that the same relationship holds true for many forms of cancer. Delicately, this pilot, diabetes and cancer can be thought of as lifestyle diseases, and that body composition is one factor which is correlated with the risk of these diseases. Here we can see the five different lenses through which to view body composition. So at the time level, we mostly hydrogen and oxygen, the word elements on a carbon skeleton with trace elements making it the rest. At the molecular level, we mostly water with fats, proteins and minerals making up the remainder. At the cellular level, where you predominantly cell mass, extra cellular solids, that's ECS, that ECF is extra cellular fluids and fat. And functionally, which we're most often interested is joint modify is muscle and fat, and then other substances like blood and bone. So within the functional assessment of body composition, there are a number of different models that can be used to describe body composition. As we can see, whether we're using a two, three or four component model, the common factor is fat mass. So different techniques are required for different analyzes, but most techniques can identify fat mass or a fat percentage analysis. So while fat is a common denominator between these different assessments of body composition, there are still different types of fat. So optimal fat is critical for optimal health. It is necessary for healthy cell and system function. At the minimum, it's 3% for men and 12% for women. Fat can be stored under the skin, known as subcutaneous or visceral fat, and deeper fat around the organs. It's the visceral fat that can be the dangerous for health due to its proximity to the organs. Here are a number of different ranges for recommended levels of body fat, but broadly speaking and optimum body fat percentage could be generalized to be between eight and 35% if you're unsure what these different levels of body fat look like, This slide provides a rough depiction of how body shapes change with increasing levels of body fat. For similar levels of body fat percentage, there are different fat distributions referred to as Android fat, or going away fat core locally there's the apple or pear body shape. The Android shape is more associated with health risk as the fat is stored around the organs. So humans are becoming increasingly overweight innovative. This is due to a number of reasons, but it can be summarized simply, as we are consuming more of energy. As wealth increases and high energy convenience foods become more prevalent, we're also burning less and less energy as tasks which were typically performed manually and burned like calories, and they are performed by technology machines. So this combination of more energy being consumed and less being burned has resulted in an explosion in obesity that's particularly in wealthy first world countries, and with that, an increase in preventable chronic diseases. So as many physical characteristics, there is a genetic component, and there are rare forms of obesity that are result of gene mutations which influence appetite or energy homeostasis. However, given that human genetics have changed little in the past 50 years, and obesity rates have increased significantly, the impact of genes on obesity are quite small. Instead, lifestyle choices driving the change in obesity rates, the magnitude of chronic health conditions associated with obesity are large, expensive and largely preventable, so being overweight has been demonstrated to impact cardiovascular disease, cancer, high blood pressure, hypertension and type two diabetes. Type Two Diabetes is a situation where the body becomes resistant to insulin. Type one diabetes is an unable genetic condition that usually in young people, where the body cannot produce insulin. Being overweight or obese can impact sleep as we naturally, plays a critical role in physical and mental health. However, it's not only being overweight that has health implications. Being underweight can also carry significant risks. In women, it can lead to menstrual abnormalities and associated health complications with that. In women, it can lead to osteoporosis. So that's a condition characterized by weaker bones, which makes it more susceptible to fracture. But physiologists and dietitians can calculate metabolic rate using equations to determine the basal metabolic rate, that's the minimum energy required to maintain physiological function, so it is dependent upon age, gender and body mass. Resting metabolic rate can still be calculated, and it's similar, but it's measured under different conditions. This is important because knowing the metabolic rate consists professionals to prescribe nutrition and exercise, inventions to manage body composition. So once we know roughly how much energy a person needs to function at rest, we can apply an activity factor to this BMR to determine daily energy requirements, in total, to maintain weight, and use this as a guide to monitor nutritional intake, to manage weight. So in summary, body composition is the compartmentalization of body tissues. Body fat is essential for health, but there is an optimal range and lifestyle choices impact body composition. So overweight and obesity has a range of adverse health risks, and likewise, underweight is also the health risk. Exercise professionals look at the energy requirements and we can calculate those to help us by nutrition and exercise interventions to help people with weight, composition. ANTHROPOMETRY we will build on understanding of body composition and the means available for body composition assessment. By the end of this lecture today, you will understand how to measure and interpret body composition using both field and lab based methods. So assessment methods for many physical tests, including anthropogenic can be divided into field based tests and lab based tests. Generally speaking, field tests are more simple, quicker and cheaper to administer, but can lack the accuracy and sometimes the detail of lab methods. Lab methods, on the other also, are far more accurate, of the more expensive compared to field tests have much tighter testing protocols involving more time, and they make them more challenging to administer to administer. Two groups, we'll go through some of these assessments. Now, with all testing, there are protocols to ensure there are reliability to test. So for height and weight, an example would be weighing someone with shoes off for the first time and then shoes on the next time will result in increasing weight. That's the weight of their shoes, but we could mistakenly conclude that they'd increase weight. So an easy way to avoid confusion with all their testing protocols is to have standardized testing. So with for height, we would remove shoots, we would stand straight and have the feet together. On this last point, think about the difference in height of a couple of centimeters, and the difference between your feet together and your feet wide apart. For body weight, ideally, your point is in minimal clothing, which is not always convenient or comfortable, but something that we should consider for if we're doing some athlete populations, particularly swims or water ball athletes, we're trying to get them with straight from the pool where they have weight here, because that would affect the measurement as well. Body mass index, or BMI, is a common method to non invasively assess body composition in terms of overweight and absent, using just height and weight. So it is based on the concept that individuals with lower body fat will have a lower BMI. However, that's not always accurate in the sense that a heavily muscular athlete can appear overweight or even obese, although they have a metabolically healthy tissue in terms of they have a lot of muscle mass. So here is an example of a classification table which outlines for adults, normal BMI, overweight, obesity and severe obesity would be based upon that relationship of height and weight. Though there's an illustration as discussed in BMI, it's very well researched, and there is really strong relationships between BMI and health complications, such as diabetes, hypertension, coronavisis, heart disease. So colitheasis is the formation of gallstones and hardened deposits within the fluid of the gallbladder, which is small organ under liver, Corona heart disease. So that's CHD. So this BMI chart doesn't even show obesity, which is a BMI over 30 under the risk of higher BMI through the range of normal and overweight as alluded to, BMI is a pretty useful tool for measuring antibiotic at the population level, as for most people, weight increases with percentage of body fat. However, it doesn't directly measure fat mass. Therefore at an individual level, it might not, might not necessarily be a great measure. So for example, if you lose three kilograms of muscle and gain three kilograms of fat to body mass index, let's say very muscley individuals are often considered overweight or obese, and the elderly can have non representative BMI due to age associated muscle atrophy or decreasing height. It's important to know the limitations of tests, as they will influence your interpretation and interventions. This involves another very common method to assess body fat. They are very important to measure. They are reliable and valid. However, they become slightly invasive because it provides some touching but there are a range of sites that can be used to make the testing a little bit more comfortable. It involves measuring the two layers of subcutaneous fat beneath the skin, and it can provide an estimation of some overall fatness. I talked about reliability. It can have a small error. There's small error associated with every test, but the more you practice, and if you're likely credited level one anthropometrist, you've practiced enough that your error is acceptably low. There's a number of different summation sites. You have seven sites, which provides a good overall view of the body, but sometimes it might only be three or four sites, and sometimes there's an site model as well. We'll be practicing involved in the lab. Whilst it appears a fairly straightforward practice, it is important to practice to get a feel of, first of all, to get an accurate landmark, because there are specific sites that we take a measure. Then also to get a feel of what an appropriate pinch is. So we don't get sometimes it's easy to pinch the muscle inside the sample, which gives it a bigger ring in a lower ring. And if all measures are always taken on the right side of the body, where they can, ideally, we carefully measure and mark the site with a permanent marker. I grabbed this info between the thumb, index finger, just to get a slight fold. We replace the calipers just below that pinch, hold for two seconds and then release. And we do multiple measures at the same site to get valid readings. Some of the sites that we take would be the medzilla, the abdominal, the thigh, triceps and biceps, and it's also subscapular, suprailiac, medial calf, and suppress Mala so there are several methods by the number of different sites, whether it's 34678, and each different summation has a conversion to body fat percentage. So it depends on the number of access sites you have. Some can be uncomfortable for some people. So then you have different samples that you can use to know that the formulas give you body density, but you need to use the serum equation to convert percent with a series a published researcher from the 60s, and it's not the Apple program on your phone. Here are some other methods that you can use to value to test my body fat. So based on the clients that you work with or the sporting organization, they may have a different protocol. So it's important that you're familiar with one specific requirements, and also important that you keep using the same protocol. You cannot compare a three site to a seven site. You compare the three side to three side, or a seven side to seven side. As far as assessments go, gith measurement is about as basic as it can get. However, the power and the surface of the test, it's easy to learn, it's easy to administer. It inexpensive, and the value of information and the relationships to health, it's actually a really good test. As well as the waste, there's also a full body assessment, which will involve measuring other areas. So it's really important to practice these you're entering someone else's physical zone. You're touching. It's a minimal touch, but you're still touching. So whilst trying to accurately place a tape and read small writings, it can be quite challenging, so it's really important to practice these you can also measure a mid thigh, thigh, forearm and cut. I stated earlier there was a waist to hip ratio, and given the low cost of the test, information value is incredibly high. Higher scores of waste relative to keep circumference indicates higher abdominal fat, which is an increased risk of cardiovascular disease, and that's the android or apple shape that we talked about in the previous lecture. There are optimal ranges, and there's risk related to waste to heat ratios. So this is some really important information for such a non invasive and simple test, but also laboratory tests which become more complicated and provide more detailed information. So these include the scans hydrostatic weight, air displacement and biological impedance, which we'll go through now. So a dual energy X ray, or DEXA, is a low radiation X ray scan of the entire body, which can estimate body fat and bone density. It has mass less radiation than an x ray, and it's able to identify fat and bone and it can actually provide excellent detail on fat mass and really important information on bone density. So that bone density so that bone density information is quite important for specific populations. It could also be done in conjunction with a more frequently performed field test. There's a comparison, because it's expensive for them and requires professional expertise. For example, The Sporting Club might do one test in their preseason as a really detailed assessment. At the same time, they'll do skin folds, and they'll use that skin fold comparison to Dexter skin to track their athletes with multiple skin fold assessments throughout the season. Hydrostatic weighing. This is where the subject is weighed on land, and then when they land fully submerged in water, and relies on the difference between underwater and out of water weights and the density of the body and water displacement. This is not as popular due to the non population scans, due to the inconvenience of being weighed underwater, and it requires the specialized equipment that subject must also exhale or their air and then remain underwater, which makes it a somewhat difficult process. There's also air displacement, which was used to overcome the need to submit some of the water, and also calculated based upon weight and air displacement. But again, it's less popular test because it's time consuming and expensive. And finally, we have bio electrical impedance analysis. Now, whilst you could argue that this is a field measure rather than a lab measure, it does require a specialized piece of equipment. So that's what's included here. This is where a low level current is passed through the body to estimate the body fat percentage, given that lean tissue contains more water than fat tissue, the level of resistance to the current, indicating that lean versus fatness. This is certainly much cheaper than other lab based methods that's not as reliable and only provides a general measure of body composition. It could also be influenced by hydration status and even moisture on hair and clothes. So whilst we understand we try standardize all our tests, we can see that there's more errors can be introduced into a b by a test. So in summary, body composition can be assessed by field or lab tests. The field tests are cheaper, they're quicker and but they're less accurate than lab the lab much more accurate, much more detailed, but they can be expensive. They're also prohibitive for large groups, because the time requirements for the streets protocols, BMI home weight only, and that has a great relationship to health risk. So does he have to weight ratio, girth OS detects remains the gold standard for body composition. It is a little more expensive regarding specialized equipment and harder to get body composition. Assessment for exercise and sports science professionals is a really important tool in the assessment toolbox, and this will form part of our labs where we get a lot of hands on experience, learning how to do girths and skin vaults, learning to I'm encourage you to be involved in the lab as much as possible, to practice these skills. Thank you for listening to today's lecture if you have any questions, please ask your tutors or send His names. Thanks
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4. Metals and Non-metals Learning Objectives By the end of the lesson, you will be able to: ☑ distinguish between metals and non-metals ☑ describe the physical and chemical properties of metals and non-metals ☑ list the uses of some metals and non-metals MINERALS AND ORES You have learnt that all materials Here is the exact text from the image:are made up of basic substances called elements, and that elements cannot be split into simpler substances by chemical methods. There are 118 known elements. Sodium, zinc, gold, mercury, iron, lead, barium and tin (metals); and hydrogen, oxygen, carbon, sulphur, chlorine, boron, neon and radon (non-metals) are some examples. Only certain unreactive elements are found free in nature. Others occur in combined states as minerals. A mineral is a solid inorganic substance that is found in nature. A mineral deposit that can be mined and from which an element or compound can be obtained profitably is known as an ore. Elements can be broadly classified into two groups—metals and non-metals. Table 4.1 Some common ores Fig. 4.1 Some common ores a. Bauxite (aluminium) b. Malachite (copper) c. Haematite (iron) d. Galena (lead) e. Apatite (phosphorus) f. Quartz (silicon) -- --- METALS All except 20 of the known elements are metals. Most metals are reactive; they combine with other elements in nature, such as oxygen and sulphur, and occur as oxides, sulphides and carbonates. Only a few unreactive metals like gold, silver and platinum are found as free metals in the Earth's crust. Physical Properties of Metals Metals are solids at room temperature, except mercury, which is a liquid at room temperature (Fig. 4.2(a)). They are generally hard and strong, with a few exceptions such as sodium and potassium, which are soft and can be easily cut with a knife (Fig. 4.2(b)). They have a metallic lustre (shine), especially when freshly cut. They have high melting and boiling points, with a few exceptions like sodium, potassium and mercury. They are good conductors of heat and electricity. Silver and copper are the best conductors of electricity, followed by gold and aluminium. Metals are sonorous. They produce a ringing sound when struck. Most metals have high tensile strength. They can take heavy loads without breaking. They are malleable. Metals, with exceptions like sodium and potassium, can be beaten into thin sheets and foils. They are ductile. Metals, with exception like sodium and potassium, can be drawn into wires. Most metals have high density. However, sodium and potassium have low density and float on water. Fig. 4.2 Special metals a. Mercury b. Sodium --- Chemical Properties of Metals Reaction with oxygen Metals react with oxygen under different conditions to form basic oxides. These basic oxides react with water to form bases. Sodium and potassium react vigorously with oxygen at room temperature. 4Na + O_2 \rightarrow 2Na_2O To prevent this oxidation, sodium and potassium are stored under kerosene. Magnesium reacts with oxygen only when ignited. It burns with a dazzling bright flame and forms a white powder of magnesium oxide. 2Mg + O_2 \rightarrow 2MgO Copper and iron react with oxygen only when heated to a very high temperature. 2Cu + O_2 \rightarrow 2CuO --- --- Reaction with water Metals react with water to form hydroxides or oxides, along with hydrogen. Different metals react at different temperatures. Sodium, potassium, and calcium react with cold water to form hydroxides. 2Na + 2H_2O \rightarrow 2NaOH + H_2 Magnesium Reacts with steam or hot water to form magnesium oxide. Mg + H_2O \rightarrow MgO + H_2 Aluminium Forms an oxide too, but this oxide forms a protective covering over the metal and prevents further reactions. 2Al + 3H_2O \rightarrow Al_2O_3 + 3H_2 Zinc Reacts only with steam. Zn + H_2O \rightarrow ZnO + H_2 Iron Reacts with steam when heated strongly. 2Fe + 3H_2O \rightarrow Fe_3O_4 + 3H_2 Copper, gold, silver, and platinum do not react with water at all. --- Activity 4.1 Teacher Demonstration Aim: To study the reaction of metals with water. [Caution: This activity should be demonstrated by the teacher, and students should stand away from the table.] Materials required: Two 200 mL beakers Pieces of sodium and calcium Forceps Knife Litmus papers Water Method: 1. Fill each beaker with 100 mL of water. 2. Using forceps and a knife, cut a small piece of sodium. 3. Dry it on a tissue paper and drop it into one of the beakers. 4. Repeat the same procedure with calcium. 5. Test the water in both the beakers with red and blue litmus papers. Observations and Conclusions: Sodium reacts vigorously and may explode. A gas is also released. The reaction with calcium is quick, though not as vigorous as that with sodium. In both cases, the red litmus paper turns blue, showing that the solutions are bases. --- Reaction with dilute acids Most metals react with dilute acids to form their salts and liberate hydrogen gas. The reaction with reactive metals like sodium, potassium, and calcium is violent. Magnesium, aluminium, zinc, and iron do not react violently. Mg + 2HCl \rightarrow MgCl_2 + H_2 Copper, silver, gold, and platinum do not react with dilute acids. --- Reaction with bases Only some metals such as aluminium and zinc react with strong bases like sodium hydroxide to liberate hydrogen gas. Zn + 2NaOH \rightarrow Na_2ZnO_2 + H_2 --- Activity 4.2 Aim: To study the reaction of metals with dilute hydrochloric acid. Materials required: Sandpaper Six test tubes Dilute hydrochloric acid Strips of magnesium, zinc, iron, tin, lead, and copper Method: 1. Clean the metal strips with sandpaper. 2. Add dilute hydrochloric acid to the six test tubes. 3. Insert a strip of metal into each test tube. Observe if any bubbles are formed in the test tubes. If no bubbles are seen, warm them gently in a beaker of hot water. 4. Observe the speed at which gas is generated. This gives an idea of the speed of the reaction. 5. Classify the metals in order of their reactivity with dilute hydrochloric acid. [Caution: Acids are corrosive and should be handled carefully.] --- Activity 4.3 Aim: To study the reaction of metals with bases. Materials required: Small piece of zinc Beaker Sodium hydroxide Method: 1. Prepare warm sodium hydroxide or caustic soda solution. 2. Drop the piece of zinc into it. Observations and Conclusions: You will notice that zinc reacts with sodium hydroxide to liberate hydrogen gas. Observations on Metals with Dilute Acids Metals like sodium, potassium, and calcium react violently with dilute acids to liberate hydrogen gas. Magnesium, aluminium, zinc, and iron also displace hydrogen from dilute acids, but the reaction is not violent. Metals such as copper, silver, gold, and platinum do not displace hydrogen from dilute acids. --- Activity Series of Metals The activity series of metals is the arrangement of metals in decreasing order of reactivity. The series in the book shows reactivity decreasing from top to bottom. Potassium is the most reactive metal while gold is the least reactive. --- Displacement of a Metal by Other Metals A more reactive metal displaces a less reactive metal from its compounds in an aqueous solution. Some examples: Mg + CuSO_4 \rightarrow MgSO_4 + Cu Zn + FeSO_4 \rightarrow ZnSO_4 + Fe Iron can displace copper from copper sulphate solution (as shown in Activity 4.4). The solution turns green, and reddish-brown copper deposits on the iron nail. Copper cannot displace iron from iron sulphate solution, showing that copper is less reactive than iron. Cu + FeSO_4 \rightarrow \text{No reaction} Question: What do you think will happen if you place a silver spoon in copper sulphate solution? --- Activity 4.4 - Displacement Reaction Aim: To study a displacement reaction. Materials Required: Test tube Iron nail Copper sulphate solution Method: 1. Fill the test tube with copper sulphate solution (blue in colour). 2. Place the clean iron nail in the solution. Observations and Conclusions: After about an hour, the solution changes to green, and a reddish-brown deposit is formed on the iron nail. --- Corrosion of Metals Corrosion is the destruction or damage of a material due to chemical reaction. Rusting of iron happens when iron is exposed to moist air, forming a reddish-brown layer of rust. Rust is iron oxide, which eventually flakes off, damaging the object. Definition written on the page: "Slow eating of a metal’s surface due to oxidation is called corrosion of metals." --Observations on Metals with Dilute Acids Metals like sodium, potassium, and calcium react violently with dilute acids to liberate hydrogen gas. Magnesium, aluminium, zinc, and iron also displace hydrogen from dilute acids, but the reaction is not violent. Metals such as copper, silver, gold, and platinum do not displace hydrogen from dilute acids. --- Activity Series of Metals The activity series of metals is the arrangement of metals in decreasing order of reactivity. The series in the book shows reactivity decreasing from top to bottom. Potassium is the most reactive metal while gold is the least reactive. --- Displacement of a Metal by Other Metals A more reactive metal displaces a less reactive metal from its compounds in an aqueous solution. Some examples: Mg + CuSO_4 \rightarrow MgSO_4 + Cu Zn + FeSO_4 \rightarrow ZnSO_4 + Fe Iron can displace copper from copper sulphate solution (as shown in Activity 4.4). The solution turns green, and reddish-brown copper deposits on the iron nail. Copper cannot displace iron from iron sulphate solution, showing that copper is less reactive than iron. Cu + FeSO_4 \rightarrow \text{No reaction} Question: What do you think will happen if you place a silver spoon in copper sulphate solution? --- Activity 4.4 - Displacement Reaction Aim: To study a displacement reaction. Materials Required: Test tube Iron nail Copper sulphate solution Method: 1. Fill the test tube with copper sulphate solution (blue in colour). 2. Place the clean iron nail in the solution. Observations and Conclusions: After about an hour, the solution changes to green, and a reddish-brown deposit is formed on the iron nail. --- Corrosion of Metals Corrosion is the destruction or damage of a material due to chemical reaction. Rusting of iron happens when iron is exposed to moist air, forming a reddish-brown layer of rust. Rust is iron oxide, which eventually flakes off, damaging the object. Definition written on the page: "Slow eating of a metal’s surface due to oxidation is called corrosion of metals." Uses of Metals (Continued) Aluminium Used in high-voltage electric lines. Alloys like duralumin and magnalium are used in aircraft and automobile bodies. Used for making aluminium foil and cooking utensils. Copper Good conductor of electricity → Used in electrical wires, cables, motors, and transformers. Good conductor of heat → Used in the bottoms of stainless steel vessels. Zinc Used to make corrosion-resistant galvanised iron (GI) pipes and sheets. Used as an electrode in dry cells. Other Metals Gold and silver → Used in jewellery. Lead → Used in electrodes of lead storage batteries (used in automobiles and inverters). Chromium → Used for electroplating iron to give a shiny, corrosion-resistant finish. --- Looking Back (True/False Statements) 1. Gold, silver, and platinum are found in the Earth’s crust as free metals. → True 2. Most metals are solids that are soft. → False 3. Metals such as zinc and magnesium react with dilute acids to liberate oxygen. → False 4. A less reactive metal displaces a more reactive metal from its aqueous solution. → False 5. The chemical name of rust is zinc oxide. → False (Rust is Fe₂O₃.xH₂O) 6. Coating zinc objects with iron is called galvanising. → False (Galvanising is coating iron with zinc) Non-Metals Physical Properties of Non-Metals Exist as gases or solids at room temperature (except bromine, which is liquid). Not as hard as metals (except diamond, which is very hard). Low tensile strength and low density. Low melting and boiling points (except graphite). Not sonorous (do not produce a ringing sound). Not malleable or ductile (cannot be beaten into sheets or drawn into wires). Do not have lustre (except iodine and graphite). Bad conductors of heat and electricity (except graphite, and silicon under specific conditions). --Chemical Properties of Non-Metals Reaction with Water Most non-metals do not react with water. Highly reactive non-metals (e.g., phosphorus) catch fire in air, so they are stored in water. Fluorine, chlorine, and bromine react with water to form acids. Reaction with Oxygen Non-metals react with oxygen to form acidic or neutral oxides. Carbon and sulfur react with oxygen to form acidic oxides, which dissolve in water to form acids. Some oxides (e.g., CO, N₂O) are neutral and do not form acids. Examples: Carbon + Oxygen → Carbon Dioxide (CO₂) CO₂ + Water → Carbonic Acid (H₂CO₃) Sulfur + Oxygen → Sulfur Dioxide (SO₂) SO₂ + Water → Sulfurous Acid (H₂SO₃) Reaction with Acids Unlike metals, non-metals do not replace hydrogen in acids. Silicon reacts with hydrofluoric acid (HF). --Uses of Non-Metals Hydrogen Used in the manufacture of ammonia and industrial chemicals. Used in vanaspati (a cooking oil). Oxygen Used in breathing support systems in hospitals. Used with other gases in equipment to weld metals. Sulphur Used in the manufacture of sulphuric acid, sulphur dioxide gas, and other industrial chemicals. Used to make pesticides for agriculture. Used in vulcanising rubber (making it harder) and in gunpowder. Nitrogen Used in the manufacture of ammonia and nitrogenous fertilisers like ammonium nitrate and ammonium sulphate. Used as an inert gas in processed food packaging to prevent rancidity. Silicon Used in making semiconductors for microchips. Silicates (oxides of silicon) are used in making glass. Other Non-Metals Phosphorus: Used in making fertilisers (superphosphates). Chlorine: Used for disinfecting drinking water. Argon: Used in welding stainless steel and filling electric bulbs. Helium: Used in balloons for meteorological observations. Neon: Used in fluorescent lights for advertisement displays
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