Chemistry crossword

1234567
Across
  1. 3. power of hydrogen
  2. 4. foundation for all life on earth
  3. 6. Used in x-ray tubes
  4. 7. collagen insulin
Down
  1. 1. The study matter and how it changes
  2. 2. physical property of matter
  3. 3. super heater matter
  4. 5. To brittle in pure form