Across
- 5. created the periodic table
- 7. first element on the periodic table
- 10. the total number of protons an nuetrons
Down
- 1. a display of chemical elements
- 2. the number of protons in the nucleus
- 3. positively charged central core of atom
- 4. horizontal rows in the periodic table
- 6. subatomic particle with a negative charge
- 8. vertical columns labeled 1 through 18
- 9. one of two or more species of atoms