How many valence electrons does phosphorus have?

1 Answer
Nov 3, 2015

Answer:

5

Explanation:

There are two ways to find out. Either you take a look at your periodic table and look at which group number #P# belongs (this can be seen on upper portion) or you can draw the electron configuration of #P# atom based on its atomic number (which is 15).

http://sciencenotes.org/hd-periodic-table-wallpaper-muted-colors-2015/

According to the periodic table above, phosphorus belongs to Group 5A. Therefore, Its valence electrons should be 5.

Let's check using the electron configuration:

#1s^2# #2s^2# #2p^6# #3s^2# #3p^3# = 15 electrons = atomic number of #P#

The outermost orbitals, #3s^2# #3p^3#, contains 5 electrons.

Thus, valence electrons for #P# is 5.