The reaction of sodium in terms of names of substances and numbers of atoms involved can be represented as follows:

4Na(s) + O2(g) → 2Na2O(s)

This equation indicates that four atoms of sodium (4Na) react with one molecule of oxygen (O2) to produce two molecules of sodium oxide (2Na2O).

In this reaction, each sodium atom loses one valence electron to oxygen, resulting in the formation of positively charged sodium ions (Na+) and negatively charged oxide ions (O2-). These ions then combine to form the ionic compound sodium oxide (Na2O).

In summary, the reaction involves the transfer of electrons from sodium atoms to oxygen atoms, resulting in the formation of sodium oxide.