1.2 Phases and Classification of Matter

• Solids and liquids matter because they take up space and have mass.
• If gases did not take up space, a balloon would stay collapsed rather than inflate.

• The three states of matter are solids, liquids and gases.
• Both liquid and solid samples have volumes that are not under pressure.

• Solid, liquid, and gas are the most common phases of matter.

• The interiors of stars are home to a fourth state of matter.
• The presence of charged particles in the air creates unique properties that justify their classification as a state of matter distinct from gases.
• In addition to stars, plasmas can be found in other high-temperature environments, such as lightning strikes, television screens, and specialized analytical instruments used to detect trace amounts of metals.

• There is a torch that can be used to cut metal.

• In a small cell in a television, the ultraviolet light from the sun causes the screen to appear a specific color.
• The image you see is made up of tiny dots of color.
• This is where you will encounter it.

• Some samples of matter seem to have the same properties.
• This can happen when the sample is small.
• We can pour sand as if it were a liquid because it is composed of many small grains of solid sand.
• When it is a mixture, matter can have more than one state.
• Clouds look like gases, but they are actually a mixture of air and water.

• The force it takes to accelerate an object is one way to measure its mass.
• It takes more force to accelerate a car than a bicycle because the car has more mass.
• A balance can be used to compare the mass of an object to a standard mass.

• Weight is not related to mass.

• The force is proportional to the object's mass.
• The mass of an object does not change as the force of gravity changes.
• An astronauts mass doesn't change just because she goes to the moon.
• The moon's gravity is only one-sixth that of the earth's, so her weight is only one-sixth.

• Beer is made from water, yeast, grains, malt, hops, and sugar, with no actual loss of substance, while batteries are made from water, yeast, grains, malt, hops, and sugar, with no actual loss of substance.
• The total mass of the substances does not change, even though the OpenStax book is available for free at http://cnx.org/content/col11760/1.9 into ethanol and carbon dioxide.
• In a lead-acid car battery, the original substances that are capable of producing electricity are changed into other substances that do not produce electricity, with no change in the actual amount of matter.

• Even though this law holds true for all conversions of matter, there are few convincing examples because we rarely collect all of the material produced during a particular conversion.
• All of the matter in the original food is preserved when you eat, digest, and absorb it.
• It is difficult to verify by measurement because some of the matter is incorporated into your body.

• Consider the gold element.
• If you wanted to cut a piece of gold in half, you would have to repeat the process until it was so small that you couldn't cut it in half.
• The atom would no longer be gold if it were divided further.

• One gold atom is represented by each sphere.

• The Greek philosophers Leucippus and Democritus came up with the idea of atoms in the 5th century BC.
• It wasn't until the early 19th century that the hypothesis was supported with quantitative measurements by a British teacher.
• Since that time, repeated experiments have confirmed many aspects of the hypothesis, and it has become one of the central theories of chemistry.
• Some aspects of the atomic theory are still used, but with minor revisions.

• The size of an atom is hard to imagine.
• One of the smallest things we can see with our eyes is a single thread of a spider web.
• It is almost impossible to see the cross-section of a single strand without a microscope.
• It would take about 7000 carbon atoms to span a strand of a single carbon atom.
• If a carbon atom was the size of a dime, the cross-section of one strand would be larger than a football field.

• An image of a cotton fiber obtained with an electron microscope is much higher magnification than with the optical microscope.

• The mass of an atom is hard to imagine.
• The mass of a billion lead atoms is too light to be weighed on the world's most sensitive balances.
• It would take 300,000,000,000 lead atoms to be weighed, and they would weigh less than a gram.

• Collections of individual atoms are rare.
• Only a few elements, such as the gases helium, neon, and argon, have a collection of individual atoms that move independently of one another.
• The gases hydrogen, nitrogen, oxygen, and chlorine are composed of pairs of atoms.

• Four phosphorus atoms make up one form of the element.
• One of the forms of sulfur is composed of eight sulfur atoms.
• The units are called Molecules.
• Like cans of soda in a six-pack or a bunch of joined keys on a single key ring, the atoms in a molecule move around as a unit.
• In the elements hydrogen, oxygen, and sulfur, or in the molecule found in water, there may be two or more different atoms.
• The water molecule has two hydrogen atoms and one oxygen atom.
• There are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms in a glucose molecule.
• Molecules are very small and light.
• The water molecule inside a glass of water is about the size of golf balls.

• Two or more atoms of the same element form a molecule.

• Matter can be categorized into several categories.
• There are two broad categories.
• The properties and makeup of pure substances are the same.
• A sample of table sugar has carbon, hydrogen, and oxygen in it.
• Regardless of the source from which it is isolated, any sample of sucrose has the same physical properties.

• There are two classes of pure substances: elements and compounds.
• There are more than 100 known elements, of which about 90 are naturally occurring on the earth, and two dozen or so have been created in laboratories.

• This breakdown can produce elements or other compounds.
• Mercury(II) oxide can be broken down by heat into the elements mercury and oxygen, when heated in the absence of air.

• By absorption of light, silver and chlorine can be broken down into their elements.
• The basis for the use of this compound in photographic films and photochromic eyeglasses is this property.

• When heated, many compounds break down.
• The basis of early photography can be seen in an example.

• The properties of combined elements are not the same as those in the free state.
• White crystalline sugar (sucrose) is a compound resulting from the chemical combination of the element carbon, which is a black solid in one of its uncombined forms, and the two elements hydrogen and oxygen.
• A soft, shiny, metallic solid, and free chlorine, an element that is a yellow-green gas, combine to form a compound that is a white, crystalline solid.

• The composition of Italian dressing can vary because we can make it from a variety of ingredients.
• It is not the same from point to point, because one drop may be mostly vinegar, whereas a different drop may be mostly oil or herbs.
• Chocolate chip cookies have separate bits of chocolate, nuts, and cookie dough, while granite has the same bits of chocolate, nuts, and cookie dough.

• A sports drink consisting of water, sugar, coloring, flavoring, and electrolytes mixed together uniformly tastes the same because each drop contains the same amounts of water, sugar, and other components.
• It is possible to make a sports drink with more or less sugar, but still be a sports drink.
• Air, maple syrup, gasoline, and a solution of salt in water are some examples of heterogeneous combinations.

• Tens of millions of chemical compounds result from different combinations of elements.
• Each compound has a specific composition and has physical and chemical properties which we can distinguish from other compounds.
• There are many ways to combine elements and compounds.
• There is a summary of how to distinguish between the various major classifications of matter.

• A heterogeneous mixture, a compound, or an element can be classified according to its properties.

• About 99% of the earth's crust and atmosphere are made up of 11 elements.
• One-quarter of the elements are found in the free state, and most of the elements are found in chemical combinations.

• The water has the elements hydrogen and oxygen in it.
• Water can be broken down into hydrogen and oxygen gases.
• One way to do this is with a power supply.

• The decomposition of water is shown at many levels.

• The battery is able to break down water.
• On the left and right are gases hydrogen and oxygen.
• The change is presented in a way that shows how liquid H2O separates into H2 and O2 gases.

• There are two hydrogen atoms and two oxygen atoms in the water.

• The gases have different properties.
• Hydrogen is a potent energy source and is highly flammable, but oxygen is not.
• Research into more fuel efficient transportation is one application.
• Fuel-cell vehicles (FCV) run on hydrogen instead of gasoline, they are more efficient than vehicles with internal combustion engines, are nonpolluting, and reduce greenhouse gas emissions, making us less dependent on fossil fuels.
• Current hydrogen production depends on natural gas, and FCVs are not yet economically viable.
• FCVs may be the way of the future if we can develop a process to economically decompose water or produce hydrogen in another way.

• Water is the waste product of a fuel cell that produces electrical energy from hydrogen and oxygen.

• Imagine a life without cell phones and other smart devices.
• Cell phones are made from many chemical substances and are assembled using an extensive and in-depth understanding of chemical principles.
• About 30% of elements found in nature are found within a smart phone.
• The case/body/frame is made from a combination of sturdy, durable materials that include carbon, hydrogen, oxygen, and nitrogen, as well as light, strong, structural metals.
• The display screen is made from a specially toughened glass that is strengthened by the addition of aluminum, sodium, and potassium and coated with a material to make it conductive.
• The material used in the circuit board is usually Silicon, but it can also use metals like copper, tin, silver, and gold.
• The battery is powered by a variety of materials, including iron, cobalt, copper, and polyacrylonitrile.