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