Environmental Science

2. A substance that contributes hydroxide ions to a solution.
7. Anything that occupies space and has mass.
8. The time it takes one-half of an original radioactive parent atom to decay.
10. A critical component of living organisms made up of a long chain of amino acids.
13. The smallest particle that can contain the chemical properties of an elemental.
14. A substance composed of atoms that cannot be broken down into smaller components.
15. A smaller organic biological molecule that does not mix with water.

1. Atoms of the same element with different numbers of neutrons.
3. A compound composed of carbon, hydrogen, and oxygen atoms.
4. A highly organized living entity that consists of four types of macromolecules.
5. A measurement of the amount of matter an object contains.
6. The number that indicates the relative strength of acids and bases in a substance.
9. A substance that contributes hydrogen ions to a solution.
11. A molecule containing more than one element.
12. A particle that contains more than one atom.