1. How many covalent bonds are expected to form from phosphorus in order to obey the octet rule?

To satisfy the octet rule, there has to be eight electrons in phosphorus's outermost shell. Phosphorus has five electrons in its valence shell, fluorine has seven. This means that phosphorus would have to bond to three fluorine atoms in order to have eight electrons in its valence shell without breaking the octet rule in any one of the fluorine atoms.