Across
- 2. a row of chemical elements on the periodic table
- 4. an element with the atomic mass of 11
- 7. negatively charged atoms
- 8. The number of protons in an element
- 10. an element with the atomic number of 3
Down
- 1. an atom with the smallest mass number
- 3. a column of chemical elements on the periodic table
- 5. Have one electron in their outermost layer of electrons
- 6. smallest particle of an element
- 9. 6.02x10^23