Across
- 2. Water that collects in cracks and pores in underground soil and rock layers
- 3. Something that is needed by organisms and is no infinite in its abundance in the environment; if it is exhausted, then the organisms that need it cannot survive
- 6. The sum of all living matter on Earth
- 7. A source or supply of energy that can be used to generate electric power to meet people’s needs
- 9. Any natural process that happens to Earth’s surface, such as weathering, erosion, or plate tectonics
Down
- 1. Resources that exist in the environment without human intervention
- 4. Not replaceable by natural means within a short period of time
- 5. Replaceable by natural means in a short period of time
- 8. The layer of gas surrounding a planet that is held in place by gravity