Which of these molecules has an overall dipole moment? O A. F2 B. H2S C. CH4 D. CO2

Iknow the answer is a but i don't know why

The diagrams show objects’ gravitational pull toward each other. which statement describes the relationship between diagram x and y? gravity attracts only larger objects toward one another. gravity attracts larger objects only if they are close to one another. if the masses of the objects increase, then the force between them also increases. if distance between the objects increases, then the amount of force also increases.

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins