| A | B |
|---|
| atoms | the basic building blocks of matter |
| elements | substances that are made of only one kind of matter |
| compounds | substances that are made of two or more kinds of atoms |
| nucleus | the central part of an atom |
| protons | positively charged particles |
| neutrons | neutrally charged particles |
| electrons | negatively charged particles |
| atomic number | tells you how many units of positive charge are in the nucleus |
| mass number | the sum of the proton's and electron's weight |
| isotopes | varieties of an element that differ only in the number of neutrons in their atomic nuclei |
| radioactivity | the process which the nucleus of an atom gives off radiation or charged particles |
| radioisotopes | used to detect abnormalities in organs |
| molecule | a particle of this kind, in which two or more atoms are combined and act as a single particle. |
| chemical bond | force of attraction |
| covalent bond | a chemical bond that is formed by the sharing of electrons |
| diatomic molecule | a molecule formed when two atoms of the same element combine in a covalent bond |
| ionic bond | the force of attraction between two ions |
| chemical formula | a written representation of a compound in which a chemical symbol replaces each element |
| structural formula | a kind of chemical formula that shows how atoms in a molecule are bonded to one another |
| chemical reaction | when different substances are formed |
| reactants | substances presented before the reaction |
| products | the new substances produced by the reaction |
| law of conservation of mass | mass can neither be created nor destroyed |
| mixture | a combination of substances that are physically mixed without forming new chemical bonds |
| solution | mixtures that are liquids |
| solvent | the dissolver |
| solute | the thing being dissolved |
| suspension | a mixture that separates on standing |
| colloidal dispersion | a mixture where the particles are larger than molecules or ions but too small to settle out |
| acid | any compoud that produces hydrogen ions in solution |
| base | a compound that produces hydroxide ions when dissolved in water |
| neutralization | the process of reacting an acid and a base to produce a neutral solution |
| salt | the ionic compound produced by th neutralization reation between an acid and a base |
| ph | a unit of measurement that indicates the concentration of hydrogen ions in a solution |
| indicator | a substance that changes color when the pH goes above or below a certain value |
