Across
- 3. the unit used to measure atomic mass
- 4. positive charge, located in nucleus
- 6. 1s2-2s2-2p6-3s2-3p4
- 7. the horizontal rows on the periodic table
- 10. the percent of an isotope present on earth
- 11. the vertical columns on the periodic table
- 12. neutral charge, located in nucleus
- 13. part of the alkali metals, located in period two
- 15. atomic number 36
Down
- 1. average mass of all isotopes of an element
- 2. represented by amount of protons
- 3. number of protons plus neutrons of an atom
- 5. the first element on the periodic table
- 8. negative charge, located in the shell
- 9. [Xe]
- 14. [Ar]4s2-3d6