| A | B |
|---|
| atom | the smallest particle into which an element can be divided and still be the same substance |
| electrons | the negatively charged particles found in all atoms |
| nucleus | the tiny, extremely dense, positively charged region in the center of an atom |
| electron clouds | regions inside an atom where electrons are likely to be found |
| protons | the positively charged particles of the nucleus |
| neutrons | the particles of the nucleus that have no charge |
| atomic number | the number of protons in the nucleus of an atom |
| isotopes | atoms that have the same number of protons but different numbers of neutrons |
| mass number | the sum of the protons and neutrons in an atom |
| atomic mass | the weighted average of the masses of all the naturally occurring isotopes of an element |
| element | a pure substance that cannot be separated or broken down into simpler substances by physical or chemical means |
| pure substance | a substance in which there is only one type of particle; includes elements and compounds |
| metals | elements that are shiny and are good conductors of thermal and electrical energy; most metals are malleable and ductile |
| nonmetals | elements that are dull (not shiny) and that are poor conductors of thermal and electrical energy |
| metalloids | elements that have properties of both metals and nonmetals; sometimes referred to as semiconductors |
| compound | a pure substance composed of two or more elements that are chemically combined |
| mixture | a combination of two or more substances that are not chemically combined |
| solution | a mixture that appears to be a single substance but is composed of particles of two or more substances that are distributed evenly amongst each other |
| solute | the substance that is dissolved to form a solution |
| solvent | the substance in which a solute is dissolved to form a solution |
| alloys | solid solutions of metals or nonmetals dissolved in metals |
| concentration | a measure of the amount of solute dissolved in a solvent |
| solubility | the ability to dissolve in another substance; more specifically, the amount of solute needed to make a saturated solution using a given amount of solvent at a certain temperature |
| suspension | a mixture in which particles of a material are dispersed throughout a liquid or gas but are large enough that they settle out |
| colloid | a mixture in which the particle are dispersed throughout but are not heavy enough to settle out |
