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

Question

Peyton Adams · Accepted 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).

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.

Axel Alvarado · Answer

undefined An atom's valence electron configuration determines its place in the periodic table by determining its chemical properties and reactivity. Elements with similar valence electron configurations tend to exhibit similar chemical behavior and are grouped together in the periodic table.