Across
- 3. bond between a positive and negative ion
- 5. all chemical reactions that occur in an organism
- 7. 3-dimensional region around the nucleus that shows the location of electrons
- 13. one or more substances change to produce one or more different substances
- 15. a reactant loses electrons
- 19. total number of protons and neutrons in an atom
- 20. substances that cannot be broken down into simpler substances
- 23. ability to do work
- 24. simplest part of a substance that has all properties of that substance
- 26. number of protons in an atom
- 28. central region that makes up most of the mass of a cell
Down
- 1. shown on the right side of a chemical equation. New compounds that are formed
- 2. forms when 2 atoms share one or more pairs of electrons
- 4. atom or molecule with an electrical charge
- 6. the amount of energy needed to start a reaction
- 8. reactant gains electrons
- 9. attractive forces that hold atoms together
- 10. positively charged subatomic particle found in the nucleus
- 11. amount of matter an object has
- 12. simplest particle of an element that retains all of the properties of an element
- 14. shown on the left side of a chemical equation
- 16. subatomic particle found in the nucleus that has no charge
- 17. atoms of the same element that have different numbers of neutrons
- 18. anything that has mass and takes up space
- 21. negatively charged particles
- 22. protein or RNA molecule that speeds up reactions without being permanently changed or destroyed
- 25. reduce the amount of activation energy needed to start a reaction
- 27. made of atoms of 2 or more elements