Across
- 5. groups that are up in down
- 6. a single electron or one of two or more electrons in the outer shell of an atom.
Down
- 1. a table of the chemical elements arranged in order of atomic number
- 2. elements on the left side of the periodic table
- 3. chemical/reaction on the periodic table
- 4. elements on the right side of the periodic table
- 7. periods that go from left to right