1 because it only has 1 valence electron to bond with.
How Many Covalent Bonds Can A Single Hydrogen Atom Make?
A covalent bond is a strong bond between two non-metal atoms. It consists of a shared pair of electrons. A covalent bond can be represented by a straight line or dot-and-cross diagram.
Hydrogen and chlorine can each form one covalent bond, oxygen two bonds, nitrogen three, while carbon can form four bonds
Sharing electronsYou will need to understand what covalent bonding is, and to remember some of the properties of molecules that are formed in this way.
A covalent bond forms when two non-metal atoms share a pair of electrons. The electrons involved are in the highest occupied energy levels - or outer shells - of the atoms. An atom that shares one or more of its electrons will complete its highest occupied energy level.
Covalent bonds are strong - a lot of energy is needed to break them. Substances with covalent bonds often form molecules with low melting and boiling points, such as hydrogen and water.
One, a single hydrogen only has one electron so it can only make one bond
Hydrogen has only 1 electron and it need two electron for coming stable position, so it make one covalent bond.