How does the air temperature at the bottom of a mountain compare with the air temperature at the top of the mountain? A. The air is colder at the bottom.
B. The air is warmer at the top.
C. The air temperature at the top is lower.
D. The air temperature is the same.

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o