Across
- 2. any difference between individuals of the same species
- 5. this type of change involves altering the form or appearance of a substance without changing it into a different substance
- 8. producing more offspring than can possibly survive
- 12. the smallest particle that can still be considered an element
- 13. negatively charged particles that move around outside of the nucleus
- 14. this type of change involves the production of one or more new substances
- 16. the one or two letter abbreviation for an element's name
- 17. horizontal rows on the periodic table
Down
- 1. vertical columns on the periodic table
- 3. a trait that increases an organism's ability to survive and reproduce
- 4. the process of change over time
- 6. a solid that forms from liquids during a chemical reaction
- 7. the small dense region in the center
- 9. the process by which individuals who are better adapted to their environment being more likely to survive and reproduce
- 10. a positively charged particle found in the nucleus
- 11. the number of protons in the nucleus of an atom
- 15. a pure substance that cannot be broken down into any other substance
- 18. a group of similar organisms that can mate and produce fertile offspring