The valence electron in potassium requires #6.95 xx 10^-19# #"J"# of energy to be removed. What frequency of light can do this? What type of electromagnetic radiation could do this?

1 Answer
Jul 3, 2017

Answer:

Very blue visible photons or UV photons.

Explanation:

#K# electron configuration: #[Ar]4s^1#

This electron in the #4s# orbital requires #E = 6.95*10^-19 J# to be emitted. This is merely a question of the photon's energy being that which meets this requirement, thus,

#6.95*10^-19 J = (6.626*10^-34 J*s)v#
#v = 1.05*10^15 s^-1#

Now, referring to the EMR diagram that I gaurantee you most people don't have absolutely memorized:
Wikipedia

This energy corresponds with the frequency of very blue photons (visible) or UV photons.