Across
- 2. The basic unit of a chemical element, consisting of a nucleus surrounded by electrons.
- 5. The process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.
- 9. A specialized cell transmitting nerve impulses; a nerve cell.
- 10. The smallest structural and functional unit of an organism, typically microscopic.
- 11. The force that attracts a body toward the center of the Earth, or toward any other physical body having mass.
- 12. The molecule that carries genetic instructions in all living things.
Down
- 1. The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the Earth.
- 3. A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.
- 4. Anything that has mass and takes up space.
- 6. A chemical reaction in which a substance combines with oxygen, often releasing energy.
- 7. The capacity to do work, existing in various forms such as kinetic, potential, thermal, and chemical.
- 8. A biological community of interacting organisms and their physical environment.