What does it all mean?

Edit Answers
123456789
Across
  1. 2. The unit of measure for pressure (2 letters).
  2. 4. The process of separating substances in a mixture (9 letters).
  3. 6. The process of turning a liquid into a gas(6 letters).
  4. 9. A substance made of two or more elements (6 letters)
Down
  1. 1. A change in a substance that does not affect its chemical composition (7 letters)
  2. 3. A common acid found in vinegar (6 letters)
  3. 5. A tool used to measure temperature (6 letters)
  4. 7. The smallest unit of a chemical element (4 letters)
  5. 8. A chemical reaction that absorbs heat (8 letters)