Science

123456789101112131415
Across
  1. 3. Which planet is most similar to Earth?
  2. 4. What is the type of element that has 13 protons?
  3. 7. What is the first artificial element? technetium
  4. 9. How many nonmetals are there in the periodic table?
  5. 10. Which is the last element in the periodic table?
  6. 12. Which animal was the first to go into space?
  7. 13. Which noble gas is in the 4th period of the periodic table?
  8. 15. Which element has 22 protons?
Down
  1. 1. How many of the elements in the periodic system are found in nature?
  2. 2. What is the structural unit of DNA?
  3. 5. How are the elements in the periodic table arranged?
  4. 6. Which scientist first proposed the periodic table?
  5. 8. 2nd largest planet in the solar system?
  6. 11. How many planets larger than Earth are there in the solar system?
  7. 14. What period is mercury in in the periodic table?