Across
- 2. atomic symbol is B and its atomic number is 5
- 5. is the very first element of the periodic table
- 8. has 1 valence elctron
- 9. has the secound smallest atomic number
Down
- 1. discovered in 1898 chemical symbol
- 3. has 8 valence electrons
- 4. horizonal on the periodic table
- 6. the element under hydrogen
- 7. its atomic number is 10 it is a noble gas