Across
- 1. reaction requires an input of energy (energy is absorbed)
- 3. changes the rate of a chemical reaction without being used up
- 4. uses chemical symbols and numbers to represent a given substance
- 6. process when atoms are rearranged to produce new substances
- 7. CH4 is the chemical formula for what substance
- 10. may form a solid in a solution
- 12. substances formed in a reaction
- 14. a type of catalyst found in living things
- 15. the number in front of the chemical formula
- 16. the element that has 16 protons
Down
- 2. the element in period 4 group 2
- 3. an expression that uses symbols to show the relationship between the starting substances and the substances that are produced by a chemical reaction
- 5. number written below and to the right of the chemical symbol
- 8. sign is represented by and arrow in a chemical equation
- 9. an atom with a different number of protons than neutrons
- 11. a neutral atom that gains or loses electrons
- 13. substances that participate in a chemical reaction
- 14. reaction energy is released to the surroundings