ELEMENT

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Across
  1. 3. gas in balloon
  2. 4. diagonal of block-p in Periodic table
  3. 6. liquid in VIIA
  4. 7. knife can cut
  5. 8. Atomic number is 11
Down
  1. 1. protect simple goiter
  2. 2. valence electron as 2
  3. 3. poisonous element
  4. 5. full valence electron as 8
  5. 9. Electrical conductivity