Science and Technology Notes

Material World

Characteristic Properties: Melting Point

  • Melting point: Temperature at which a substance changes from solid to liquid.

  • Characteristic property: Each pure substance has a unique melting point.

  • Identification: Compare the melting point of an unknown substance to known substances.

Characteristic Properties: Boiling Point

  • Boiling point: Temperature at which a substance changes from liquid to gas.

  • Characteristic property: Each pure substance has a unique boiling point.

  • Identification: Compare the boiling point of an unknown substance to known substances.

Characteristic Properties: Density

  • Density: Ratio between mass and volume of a substance.

  • Characteristic property: Each substance has a unique density.

  • Units: g/mL or g/cm^3 (1 mL = 1 cm^3).

  • Formula: ρ = \frac{m}{v}

Characteristic Properties: Solubility

  • Solubility: Maximum amount of solute that can dissolve in a solvent at a given temperature.

  • Characteristic property: Varies for each substance at a specific temperature.

  • Saturation level: Describes the amount of solute dissolved in a solvent (unsaturated vs. saturated).

  • Temperature effect:

    • Solid solutes: Solubility increases with temperature.

    • Gas solutes: Solubility decreases with temperature.

Characteristic Properties: Reaction to Indicators

  • Indicators: Substances that change color in the presence or absence of specific chemical species (e.g., acid or base).

  • Examples:

    • Litmus paper: Tests for acids, bases, or neutral substances.

    • pH paper: Determines the specific pH of a substance.

    • Cobalt chloride paper: Detects the presence of water.

    • Iodine: Detects the presence of starch.

    • Limewater test: Detects the presence of carbon dioxide.

Solutions

  • Solution: Solute dissolved in a solvent.

  • Aqueous solution: Water is the solvent.

  • Solute: Substance being dissolved.

  • Examples: Seawater, urine, juice, and plasma.

Solutions: Concentration

  • Concentration: Quantity of dissolved solute in a quantity of solution.

  • Formula: C = \frac{m}{V}

  • Units:

    • Grams per liter (g/L): C = \frac{m (g)}{V (L)}

    • Percentage of mass/volume (% m/V): C = \frac{m (g)}{V (mL)} × 100

  • Effect of solute/solvent:

    • Increasing solute: Increase concentration.

    • Increasing solvent: Decrease concentration.

Particle Model

  • Definition: A means of representing the behavior of matter.

  • Key concepts:

    • Matter is made up of particles.

    • All particles are in constant motion.

  • Dissolution: Solute particles spread evenly in the solvent.

Dilution

  • Dilution: Adding solvent to an initial solution, reducing the concentration and increasing the volume.

  • Amount of solute stays the same.

  • Formula: C1V1 = C2V2

Phase Changes

  • States of matter: Solid, liquid, and gas.

  • Phase change: Particles gain or lose energy.

Chemical Changes

  • Definition: Results in the formation of one or more new substances.

  • Examples in the human body: Cellular respiration and digestion.

  • Cellular Respiration: glucose + oxygen -> carbon dioxide + water + energy

  • Digestion: Process of molecules transforming into energy for the body.

Decomposition and Synthesis

  • Synthesis: Multiple reactants combine to form a single product. A + B ® AB

  • Decomposition: A molecule is broken down into multiple simpler molecules/atoms. AB ® A + B

Oxidation

  • Definition: A reaction where a substance reacts with oxygen.

  • Examples:

    • Rusting/Corrosion: Metal + oxygen -> metal oxide.

    • Fire/Combustion: Fuel + oxygen -> water + carbon dioxide.

    • Cellular Respiration: Glucose + oxygen -> energy + water + carbon dioxide.

Precipitation

  • Definition: Two aqueous solutions are mixed, and a solid precipitate appears.

  • Insoluble particles combine to form a new substance.

Transformation of Energy

  • Forms of energy:

    • Chemical: Stored in molecular bonds.

    • Thermal: From random motion of particles.

    • Radiant: Carried by electromagnetic waves.

    • Mechanical: From movement or position of an object.

    • Electrical: Movement of charged particles.

  • Transformation: Conversion of energy from one form to another.

  • Unit: Measured in joules (J).

Pure Substance

  • Definition: Made up of a single type of atom or molecule.

  • Elements: Pure substances made of a single type of atom (e.g., hydrogen, helium).

  • Compounds: Pure substances made of 2 or more types of atoms chemically bonded (e.g., water, sodium chloride).

Homogeneous and Heterogeneous Mixtures

  • Homogeneous: Uniform composition (e.g., plasma, urine).

  • Heterogeneous: Non-uniform composition (e.g., feces).

Fluids

  • Definition: Substance that can flow and take the shape of its container (liquids and gases).

  • Compressible fluids: Particles can be pushed closer together (gases).

  • Incompressible fluids: Particles cannot be pushed closer together (liquids).

  • Pressure: Force exerted by particles colliding with a surface.

  • Fluids move from a zone of high pressure to a zone of low pressure.

  • Pressure and volume of a gas are inversely proportional.

Waves

  • Frequency: Number of cycles per second (Hz).

  • Wavelength: Distance between two identical points on a wave at a given time.

  • Amplitude of sound wave: Loudness of the sound.

  • Frequency of sound wave: Pitch of the sound.

  • Sound intensity: Measured in decibels (dB).

  • Relationship between wavelength and energy: The shorter the wavelength, the greater the energy.

  • Electromagnetic spectrum: Radio and microwaves (low energy, long wavelength) to X-rays and gamma rays (high energy, short wavelength).

Deviation of Light Waves

  • Reflection: Light ray bounces off a reflective surface (angle of incidence = angle of reflection).

  • Refraction: Light bends when it passes through a translucent substance.

  • Convex lens: Causes light rays to converge (focal point).

  • Concave lens: Causes light rays to diverge.

LIVING WORLD

Tissues, Organs and Systems

  • Tissue = set of identical or different cells that work together to perform a common function

  • Organ = differentiated organism that performs one or more specific functions

  • system = set of cells, tissues, or organs that perform one or more common functions

  • Main function performed by the human body (Nutrition, Relationships, Reproduction

Digestive System

  • Parts of the digestive tract: mouth, esophagus, stomach, small intestine, large intestine, and anus.

  • Roles: Decomposition of food, absorption of nutrients and water, elimination of waste.

  • Main organs and their functions: mouth (ingestion, chewing, chemical digestion begins), stomach (churning, breaking down of proteins), small intestine (digestion, absorption of nutrients), large intestine (absorption of water, vitamins and minerals).

  • Main digestive glands: salivary glands, gastric glands, pancreas, liver, intestinal glands

  • Breakdown food to become nutrients for the body

  • Food constituents:

    • Carbohydrates: energy source in complex and simple forms

    • Lipids: Energy storage, organ protection and insulation

    • Proteins: Repair tissues and cells

    • Water: Transports nutrients, regulates body temp

    • Vitamin: regulate metabolism

    • Minerals: help in chemical reactions

    • Mechanical Change: breaking up food through chewing

    • Chemical Change: use of body secretion to break down the components of food for nutrient acquisition

Respiratory System

  • Parts: Nasal cavity, pharynx, trachea, bronchi, and lungs.

  • Role: Gaseous exchange between blood and surrounding air (oxygen in, carbon dioxide out).

  • Functions of the nasal cavity and lungs: Filter warm and cleanse the air, alveoli gas exchange for use of oxygen

Circulatory System

  • Parts: Heart, blood vessels (arteries, veins, capillaries), pulmonary and systemic circulation.

  • Function: Transportation and exchange of gases, nutrients, and waste.

  • Plasma main function: transport of blood soluble water

  • Formed elements of the blood (red blood cells, white blood cells, platelets)

    • Red blood cells; transport of oxygen and carbon dioxide

    • White bloods cells: Immune Function of recognizing foreign harmful components and generating antibodies

    • Platelets: blood clot function

  • Blood type compatibility system; Type A-AB-B-O with a + or - rhesus factor

Lymphatic System

  • Parts: Lymph, antibodies.

  • Role: Circulation of antibodies outside the blood vessels and maintain all the body’s defenses.

  • Immunity aqusition

  • Acquire Active immunity

Excretory system

  • Parts: Kidneys, ureters, bladder, urethra.

  • Role: Filter the blood, elimination of cellular waste.

  • Components of Urine (water, mineral salts, urea

  • Role of kidneys lungs and sweat glands to maintain a balanced metabolism

Nervous System

  • Central nervous system: brain spinal cord

  • Brain function controls:

  • Spinal cord: relays information from body to the brain reflex actions

  • NEURON:
    Parts: Synapse axon, dendrties associated nerves:

  • Transportation of nerve impulsion

  • Peripheral nervous system = transportation of nerve impulss from senses to the brain and from the brain to the muscles.
    Voluntary acts vs Reflex Arcs

Sensory Receptors

  • Eye components (iris, cornea, lens, retina): transformation of light

  • Ear (auditory canal, eardrum, ossicles, cochlea, semicircular canals)

    • hearing and balance function

  • Tongue, Nose and Skin:

    • Taste buds: flavors (sweet, salty, sour, bitter, umami).

    • Nasal cavity + olfactory bulb --> sense smells

    • Skin sensory receptors: feelings of pressure, temperature and pain

Musculoskeletal system

  • Skeleton main parts (head, thorax, spinal column, upper and lower limbs).

  • function performed = protection, motion and support

  • Muscoskeletal system works together for proper form and function.

  • Antagonistic Pairs of muscles help proper expansion and contraction.
    *Joints help link bone to bone with mobility for the functionality of muscles

  • types of muscles:

    • smooth
      *skeletal

    • cardiac

  • types of joint movement

    • axial

    • expansion

cell division

  • role of DNA with double helix

  • Role of DNA with genetic code
    *mitosis vs meiosis for growth regeneration and reproduction
    Cell cycle of mitosis and meiosis
    Advantages of chromosomes that determine sexual reproduction through the function of genetic diversity

Reproduction

  • Puberty: Male and female physical/physiological changes.
    *Hormone regulations in men and woman

Earth and Space

Lithosphere

  • Formation of strata in terms of layering of sediment.

  • Geological time scale, with 4 divisions (place in order):

    • Precambrian: first life appeared

    • Paleozoic: plants, fish and amphibians and reptiles. 3 times of mass extinctions

    • Mesozoic: dinosaurs appear birds evolve, Small Mammals Evolve. TWO times of mass extinctions

    • Cenozoic: primates appear, start of ice ages as well ad debatably where mass extinction occurring

  • Extinctions mass locations of certain species. Excretions when species are gone due to adaptation in environmental changes.

  • Fossil definitions for - Body - Imprints - Molds and casts