1. Classify each of the following as a homogeneous mixture, heterogeneous mixture, element, or compound:
(a) table salt, (b) blood, (c) steel, (d) planet Earth.
2. If nitrogen, N2, were pumped into your lungs at high pressure, what would happen to its solubility in your blood?
3. Why is rain or snow called precipitation?
4. Cells at the top of a tree have a higher concentration of sugars than cells at the bottom. How might this fact assist a tree in moving water upward from its roots?