Scientific Crossword

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