Across
- 2. 4.00260 is the _______weight of helium
- 5. helium is the second most ________common element in the Universe
- 6. symbol for helium
- 8. in 1868 Pierre ________discovered helium
Down
- 1. Helium is the second lightest element in the universe
- 3. atomic number of helium
- 4. Helium is classified as a ________gas and nonmetal
- 7. phase at room temperature