Question

why do some atoms react with other atoms to fom compounds where as some do not

Answer 1

They react to obtain a stable configuration and full outer shell.

The atoms which do not react already have stable configuration and are known as noble gases or inert gases

Answer 2

Atoms react with atoms of other elements to form compounds because , every atom wants to attain noble gas configuration . Atoms form covalent and ionic bonds by sharing their electrons. Atoms in which the required number of electrons match , form compounds.