Which two formulas represent compounds?

A. NaCI
B. HCI
C. H2
D. Ag

Aballoon inflated with three breaths of air has a volume of 1.7 l. at the same temperature and pressure, what is the volume of the balloon if five more same-sized breaths are added to the balloon?

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Which of these statements explains the difference between nuclear binding energy and the strong nuclear force ?