CHEMISTRY

3. One of two or more forms of a chemical element (with same # of protons and same atomic # but different # of neutrons or different atomic weights)
8. The smallest particle of a substance; a tiny bit
9. A person or thing that precipitates an event or change
11. To congeal; to solidify, set, gel; to thicken; to curdle; to clot
12. To cause to take up or combine chemically with water
14. Process of eating or wearing away gradually usually by chemical action
15. Tending to wear off or down by scraping or rubbing; inclined to annoy or irritate
16. Tending or threatening to break into open violence; liable to sudden changes

1. The act of combining or blending into a whole
2. An action in response to some influence, event etc.
4. Capable or susceptible of being liquefied or emulsified
5. To make thinner or weaker by the addition of more liquid
6. Resistant to treatment; unresponsive to stimulus; difficult to fuse, corrode or draw out; especially capable of enduring high temperatures
7. To soak thoroughly or completely; to load, fill or charge to the utmost
10. An agent or substance that slows, interferes or stops a chemical action
13. A complex made up of parts or elements put together