| A | B |
|---|
| matter | anything with mass |
| mass | measure of the amount of matter in an object |
| weight | measure of the earth's gravitational pull on an object (pound, kilogram) |
| Volume | the amount of cubic space |
| Density | mass of a substance contained in a unit of volume |
| an object floats if | its denisity is less than the density of the liquid |
| density is measured in | grams per cubic centimeter |
| density formula | m/V mass divided by the volume |
| To find the volume of an irregular object | measure the object in water and subtract the amount of water |
| Specific gravity | ratio of the density of a substance to the density of water (1 kg) |
| physical property | a property observed without changing the object |
| chemical property | describes the ability of an object to change into a new substance (baking powder changes to carbon dioxide gas during baking) |
| Solid | had shape and volume |
| liquid | definite volume but no shape |
| gas | no shape or volume, occupies the shape it is contained in |
| energy | ability to cause change in matter (heat to an icecube) |
| evaporation | is the change from liquid to gas |
| condensation | change from gas to a liquid |
| Pressure | force exerted on each unit of area of a surface |
| Pressure is measured in | Pascal = one Newton of force pushing on one square meter of area |
| When temperature of a gas increases | its pressure increases (pressure increases in a car's tire as you drive) |
| An increase in temperature causes | an increase in the volume of a gas (Charles' Law) |
| Direct variation | as one component increases the other component increases OR as one decreases the other decreases |
| A decre4ase in the volume of a gas causes | an increase in its pressure (pressing down on a pump) Boyle's law |
| Inverse variation | As one component increases the other component decreases (vice versa) |
| Element | a substance that can be broken down into other substances (109 total 89 in nature 20 synthetically) |
| Atom | smallest particle of the element that has the properties of that element |
| Elements are identified by | sybols (O for oxygen) |
| molecule | smalles particle of a substance that can exist independently and still has all the properties (most are made up of one atam but some oxygen, hydrogen, nitrogen and cholorine are made up of two atoms) |
| compound | two or more elements that have been chemically combined (they lose their individual identities) |
| Chemical formula | shorthand way of showing what is in a compound |
| Mixture | a combination of two or more substances in which the substances keep their own identities (fruit salad) |
| Compounds are classified by | acid, base, salt, and oxides |
| acid | contains one element of hydrogen (H), sour taste, vinegar |
| bases | bitter taste, stronger are slippery, contain oxygen and hydrogen, many household products |
| indicator | substance that changes color when it comes in contact with an acid or a base (Blue litmus turns red in an acid. Red litmus turns blue in a base.) |
| neutral | a substance that is neither acid nor base (do not change litmus paper) |
| salt | an acid and a base combined chemically |
| neutralization | the process of a salt forming from an acid and a base |
| oxides | compounds that are formed when oxygen combines with another element (rust -oxygen combines with iron) |
| Matter during a chemical reaction | is neither gained or lost (same number of molecules on both sides of the equation) |
| law of conservation of energy | energy can change form but it can neither be created nor destroyed |
| Democritus atomic theory of matter | 1. all matter consists of atom 2) all atams of an element are identical 3) Different elements have different atmoms 4) atoms maintain their properties in chemical reaction |
| Dalton's model of the atom | 1) matter is made up of atoms 2) atoms of an element are similar 3) atoms of different elements are different from each other 4) atoms combine with each other to form compounds |
| Thompson's model of the atom | atom is made of negative particles euqllly mixed in a sphere of positive material |
| Rutherford's model | 1) most of the atom is empty space 2) Center is the nucleus containing most of the mass and all of the positively charge of the atom 3) The scattering of particles occurs when they collide with the nucleus 4) The region of the space outside the nucleus is occupied by electrons 5) The atom is neutral because the protons in the nucleus equal the electrons in the space outside the nucleus |
