Across
- 3. all of the organisms that live in a region
- 7. the layer of the Earth that is below the crust and above the outer core
- 10. the crust and the uppermost mantle
- 11. the rate at which work is done (work / time)
- 13. the hardness or softness of a soil
- 15. layers of soil formed from the movement of the products of weathering
- 17. a grooved wheel with a rope or a cable wrapped around it
- 18. the ratio of output work to input work
- 19. a scale that measures the acidity or basicity of a solution
- 20. occurs when water enters cracks in rocks and freezes
Down
- 1. the SI unit for work
- 2. combines the element oxygen with other elements or molecules
- 4. the process of changing once-living material into dark-colored organic matter
- 5. the small holes and spaces in soil
- 6. the shape or steepness of the landscape
- 8. grinding away rock by friction or impact
- 9. the average weather of an area
- 12. plants use this type of energy from the sun
- 14. a mixture of weathered rock, rock fragments, decayed organic matter, water, and air
- 16. an inclined plane wrapped around a cylinder