Question #78f7f

1 Answer
Jul 18, 2017

Explanation:

For starters, you should know that phosphorus is located in group 15 of the Periodic Table of Elements, which implies that it needs #3# electrons to complete its octet.

In other words, a neutral phosphorus atom has a total of #5# valence electrons. When a phosphorus atom takes in #3# electrons, it gets a total of #8# electrons in its outermost shell #-># it now has #8# valence electrons.

Consequently, a phosphide anion, #"P"^(3-)# will be formed.

You can thus say that a phosphide anion has a total of #8# valence electrons. Moreover, this anion is isoelectronic, ie. it has the same electron configuration, with argon, #"Ar"#, the noble gas that follows it in the Periodic Table.