Across
- 2. atom that has lost or gained one or more electrons
- 5. starting substances
- 7. pure substance formed when two or more different elements combine.
- 8. building blocks of matter
- 9. biological catalyst that speed up the rate of chemical reactions
- 10. located at the center of the atom.
- 12. pure substance that cannot be broken
- 14. substance that lowers the activation energy needed to start a chemical reaction
Down
- 1. reactants that bind to the enzymes
- 2. stome of the same element that have different numbers of neutrons
- 3. negatively charged particles
- 4. substances forming during the reaction
- 6. chemical bond that forms when electrons are shared
- 11. positively charged atoms
- 13. compound in which the atoms are held together by covalent bonds