31. Which of the following will easily dissolve in a polar solvent?
A. gasoline (heptanes & octanes)
B. methane
C. argon
D. sodium chloride
32. The elements oxygen, nitrogen, and carbon
A. can all form covalent bonds with other elements
B. contain protons and neutrons in their atomic nuclei
C. are common elements in the molecules that make up living organisms
D. All of the above