How does an atom's valence electron configuration determine its place in the periodic table?

1 Answer
Nov 28, 2016

Answer:

Elements in a family (groups, the vertical bits) have the same number of valence electrons. The level of energy of an atom's valence electron(s) determines its period, (the horizontal lines).

Explanation:

Google Images

When you're looking for the element, try to fill in from what you're given.

E.g: Let's say you're working with Aluminium(Al),

That configuration is #1s^2##2s^2##2p^6##3s^2##3p^1#

See how it filling in across until it reached Aluminium?

Now, if you had #1s^2##2s^2##2p^6##3s^2##3p^6##4s^2##3d^7# it would be the same thing, fill in until you reach your desired place.

You would get Co, Cobalt.

Hope this helps.