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