One atmospheric compound is responsible (after it have dissolved in water) for both the general acidity of normal rainwater and the acidity of much soil. what is this compound?

Carbon dioxide is the atmospheric compound that is responsible (after it have dissolved in water) for both the general acidity of normal rainwater and the acidity of much soil. Natural rain water is slightly acidic because carbon dioxide combined with water in the air forms carbonic acid, which is a weak acid.

a force of 500                  

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."