Chemistry Terms

1. The smallest unit of an element that retains the properties of that element.
4. A change that affects the form of a substance, but not its chemical composition.
7. A solid that forms and settles out of a liquid mixture during a chemical reaction.
8. A substance that is formed as the result of a chemical reaction.
9. A visible change in color that can indicate a chemical reaction has taken place.
11. The act of maintaining or preserving something; in science, it often refers to the conservation of mass or energy.
14. A state of matter where particles move freely and fill any container they're in; often produced in chemical reactions.
16. A material that is chemically different from the substances from which it was formed.
19. A change that cannot be undone, such as most chemical changes.
20. The formation of gas bubbles, which can indicate a chemical change is occurring.
21. The amount of matter in an object, usually measured in grams or kilograms.

2. An increase or decrease in heat energy, often observed during a chemical reaction.
3. The process of a liquid turning into a gas; a physical change.
5. Initials of the principle stating that mass is neither created nor destroyed in a chemical reaction.
6. A chemical reaction in which a substance reacts with oxygen and releases energy in the form of heat and light.
10. The capacity to do work or cause physical change; can be released or absorbed during chemical reactions.
12. A change that results in the formation of one or more new substances with new chemical properties.
13. The process of a solid turning into a liquid; a physical change.
15. A process in which substances interact to form new substances.
17. A substance that takes part in and undergoes change during a chemical reaction.
18. A change that can be undone or returned to the original state.