What is the electron configuration of Li+?

1 Answer
Feb 1, 2016

Answer:

#"Li""^(+): 1s^2#

Explanation:

Your starting point here will be the electron configuration of a neutral lithium atom, #"Li"#.

A quick look in the periodic table will reveal that lithium is located in period 2, group 1, and that it has an atomic number equal to #3#.

This means that a neutral lithium atom will have a total of #3# electrons surrounding its nucleus.

http://www.chemizzle.com/p/electron-configuration.html

Its electron configuration will be

#"Li: " 1s^2 color(red)(2)s^1#

Now, the lithium cation, #"Li"^(+)#, is formed when lithium loses the electron located on its outermost shell #-># its valence electron. This electron is located on the second energy level, in the 2s-orbital.

This means that the electron configuration of the #"Li"^(+)# cation will be

#"Li"^(+): 1s^2#

To write this using noble gas shorthand notation, use the electron configuration of the noble gas that comes before lithium in the periodic table.

Helium, #"He"#, has the electron configuration

#"He: " 1s^2#

This means that you have

#"Li"^(+): ["He"]#

Here the notation #["He"]# is meant to represent the electron configuration of helium.