There are many differences between the sodium ion and sodium atom.
The charge of the sodium atom is neutral, while the charge of sodium ion is positive(+1).
The sodium atom reacts with hydrogen gas and oxygen gas.
2Na + H2 --> 2NaH
2Na + O2 --> Na2O2
The sodium ion does not react with hydrogen gas and oxygen gas.
The conductivity of Na atom is very good, while the sodium ion is a poor conductor of heat and electricity.
The Na atom is found in pure form, while Na ion has to be combined with anions to form a stable compound.
Na is a neutral form of the sodium atom. Na+ on the other hand has a positive charge of 1. This + means that the atom has lost 1 electron, making it's charge more positive that it was before. This can also be read as Na needing one more (+1) atom in order to become neutral once again.