Reactions between atoms occur when: A :an atom seeks to fill its outer shell of electrons
B :an atom seeks to balance its positive and negative charges
C :the reaction will result in paired electrons

A :an atom seeks to fill its outer shell of electrons

Explanation:

Reactions between atoms occur due the desire of an atom to fill their outer shell electrons.

The driving force for many interatomic bonding is the tendency to have completely filled outer energy levels like those of the noble gases.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.