| A | B |
|---|
| acid | a compound that turns blue litmus paper to red and forms salt when it reacts with a base |
| atomic number | the number of protons in the nucleus |
| base | a compound that turns red litmus paper blue and that forms a salt when it reacts with an acid |
| chemical change | a change in matter that results in one or more new substances with new properties |
| electron | a negatively charged particle in an atom |
| indicator | a substance that changes color when mixed with an acid or a base |
| ion | an electrically charged atom |
| model | something used or made to represent an object or to describe how a process takes place |
| neutralization | the reaction between an acid and a base |
| neutron | a particle in the nucleus of atom that has no electric charge. |
| nuclear fission | the splitting of the nucleus of an atom, releasing great amounts of energy |
| nucleus | the dense, central part of an atom |
| physical change | a change in size, shape, or state of matter, with no new kind of matter being formed |
| polymer | an organic compound consisting of large molecules formed from many smaller, linked molecules |
| proton | a positively charged particle found in the nucleus of an atom |
| radioactive element | an element made up of atoms whose nuclei break down, or decay, into nuclei of other atoms |
| salt | a compound that can be formed when an acid reacts with a base |
