Chemistry

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Across
  1. 4. A chemical reaction that becomes colder due to taking energy from the surroundings
  2. 5. A characteristic or trait of a substance that helps us describe or identify it.
  3. 7. The smallest particle of matter
  4. 9. The central part of the atom where protons and neutrons are found
Down
  1. 1. A type of change that can be reversed (ie water melting)
  2. 2. A substance made up of only one type of atom
  3. 3. A chemical reaction that gives off heat to the surroundings.
  4. 6. A process where substances interact to form new substances
  5. 8. A type of change that is not reversible and results in a new product