Periodic Table

1234567891011
Across
  1. 2. / ...deficiency affects about two billion people in the developing world and is associated with many diseases
  2. 5. / It is the ninth most abundant element in the universe
  3. 7. / It has zero neutrons
  4. 8. / The element forms about 77% of Earth's atmosphere
  5. 10. / It is found in salt
Down
  1. 1. / It is the least dense solid element
  2. 3. / Most reactive non-metal
  3. 4. / One of its allotropes is diamond
  4. 6. / Rarest element in the world
  5. 9. / In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal
  6. 11. / It is necessary to sustain most terrestrial life as it is used in respiration