The number of covalent bonds that an atom tends to form is equal to the number of valence electrons.
Step-by-step explanation:
Covalent bonds are formed between non-metals by sharing of the equal number of valence electrons between the two atoms. The valence electrons are the number of electrons in the outermost shell of the atom. These valence electrons share between the atoms and from bonds. eg. are NH3 and H2.
The sharing of valence electrons complete the octet rule and covalent bonds are formed.