Which event would be impossible to explain by using John Dalton’s model of the atom? An iron atom emits particles when it is struck by light.
An oxygen atom combines with two hydrogen atoms to form water.
An acid reacts with a base to form salt and water.
The atoms in sodium metal react with water.

dipole moments occur when there is a separation of charge. they can occur between two ions in an ionic bond or between atoms in a covalent bond; dipole moments arise from differences in electronegativity. the dipole moment is a measure of the polarity of the molecule.

explanation:

in inorganic chemistry -dipole moment ( μ ) is the measure of net molecular polarity, which is the magnitude of the charge q at either end of the molecular dipole times the distance r between the charges. μ = q × r.