Answer:
1
Step-by-step explanation:
An unknown element, X, is a nonmetal that contains seven valence electrons. Element X most likely forms 1 covalent bond.
Nonmetals gain the electron to complete the octet and form anion. Consider the example of halogen.
When it combine with another halogen atom they form covalent bond. There are seven valance electrons in outer most orbital of halogen atom. By combining with other halogen atom they form one covalent bond and complete the octet.
For example:
Cl atom combine with other Cl atom and form Clâ‚‚.