Which statement about an element’s average atomic mass is correct? a. it is determined by counting the number of isotopes in a sample of the element. b. it is equal to one-twelfth the mass of the most common isotope. c. it is a weighted average, so common isotopes have a greater effect than uncommon ones. d. it is based on an isotope’s charge, so negatively charged isotopes have a greater effect than positive ones.

1) a. water molecule breaks up into hydrogen and oxygen on passing electricity. does this involve breaking intermolecular or intramolecular forces of attraction. explain b. on boiling water changes to water vapor. does this involve breaking intermolecular or intramolecular forces of attraction. explain methanol evaporates faster than water. contrast the intermolecular forces and the vapor pressures of methanol and water?