| A | B |
|---|
| Substance | either an element or a compound |
| Element | 1 of over 100 substances found on the periodic table |
| Compound | a substance in which two or more atoms are combined |
| Mixture | a combination of 2 or more substances that are not always made up of the same amounts and are not chemically combined |
| Homogeneous mixture | a mixture that looks the same throughout |
| Heterogeneous mixture | a mixture where the individual properties of the substances that have been mixed can be seen |
| Physical property | any characteristic of a material that can be observed without changing the identity of the substance |
| Physical change | a change in size, shape or physical properties |
| Chemical property | a characteristic of a type of matter that indicates whether it can react with another substance |
| Chemical change | a change from one substance to another |
| Solid | A phase of matter where the atoms can only vibrate and not fly around or roll over each other |
| Liquid | a phase of matter where atoms can roll over each other but not fly around |
| Gas | the phase matter that consist of atoms that can fly around |
| Plasma | a phase of matter that consists of ions at a very high temperature |
| Melting | the phase change from a solid to a liquid |
| Freezing | the phase change from a liquid to a solid |
| Evaporation | the phase change from a liquid to a gas |
| Condensation | the phase change from a gas to a liquid |
| Sublimation | the phase change from a solid directly to a gas |
| Kinetic theory of matter | the idea that all matter is made of particles in constant motion |
| Atom | the smallest building block of matter |
| Proton | the positive particle inside the nucleus of the atom |
| Neutron | the particle inside the nucleus of the atom that has no charge |
| Electron | the particle with a negative charge that is inside the atom but not in the nucleus |
| Nucleus | the central part of the atom that contains the protons and the neutrons |
| Energy level | the locations outside the nucleus where the electrons are located |
| Atomic number | the number of protons in the nucleus of the atom |
| Mass Number | the total number of protons and neutrons in the nucleus of the atom |
| Isotopes | atoms of the same element that have different numbers of neutrons |
| mass | the measure of the amount of matter in an object |
| volume | the amout of space taken up by an object |
| density | mass divided by volume; how tightly the atoms in a substance are packed |
