What is the mass, in kilograms, of (3.96x10^26) molecules of water?

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

Awoman's basketball has a circumference between 28.5 and 29.0 inches and a maximum weight of 20 ounces (two significant figures). what are these specifications in units of centimeters and grams?

Witch two conditions can limit the usefulness of the kinetic molecular theory in describing gas behavior?