Question about a covalent bond....?

In my textbook, there is a picture of an element with 2 electrons(paired together) in the first shell, and 5 electrons in the 2nd or outer shell, 2 of the electrons are paired together, and the other 3 are single in the shell. The question is how many covalent bonds could this atom form, and the correct answer it gives is 3. I don't understand. I thought it would be 5, because there are 5 electrons in the outer shell. thanks if you can explain