Which of the following best describes physical weathering?
a. a series of chemical changes that wears away at rocks
b. the movement of rocks from one area to another
c. any large-scale event such as volcanic eruptions or earthquakes
d. a process that breaks down large rocks into smaller pieces

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.

Your sense of touch depends upon: a. direct contact b. heat chemical c. reactions d. pain

Add solid urea to a beaker of water. the beaker gets very cold. is δh favorable or