Across
- 3. small, dense region consisting of protons and neutrons at the center of an atom.
- 4. regions surrounding the atomic nucleus containing a specific number of electrons.
- 5. with a positive electric charge
- 7. a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.
Down
- 1. has a neutral charge
- 2. has a negative charge
- 6. the impulse for which a chemical substance undergoes a chemical reaction, either by itself or with other materials, with an overall release of energy.