Two atoms will react if in so doing both will obtain completely filled outer shells.
Any reaction has to have more than 2 atoms of differing compounds.
You cannot have one atom of gold for example, and magically turn it into silver.
Two magnesium atoms.
Two molecules of ammonia contain 6 hydrogen atoms.
covalent
Two or more atoms bonded together for a molecule or compound.
They often form a diatomic molecule.
When atoms react, electrons are shared or transferred.
When two identical atoms react, a chemical bond is formed. Sometimes the bond can be polar, non polar, or ionic.
Two magnesium atoms.
Chlorine
Two molecules of ammonia contain 6 hydrogen atoms.
Two (or more) substances react and new substances are formed.
Two atoms will react if in so doing both will obtain completely filled outer shells.
Two or more atoms bonded together for a molecule or compound.
sodium
covalent
A covalent bond.
You think probably to oxygen.