Question

Help please-

Find the elements oxygen and carbon on the periodic table. Based on their location, which one would you expect to have more valence electrons in their outer energy shell and why?

Answer 1

Oxygen and Carbon are in the non-metal section. Both are in 2nd period while Carbon is in group 4A and Oxygen is in group 6A.

Oxygen has more valence electrons than carbon. I wish I could give you a more accurate explanation why on paper, but all you need to do is count the electrons on the largest shell.

Here's the orbital notation of Carbon: 1s^2 2s^2 2px^1 py^1

Carbon's largest shell is 2. Count the electrons on shell 2, and you get 4 valence electrons.

Orbital notation of Oxygen: 1s^2 2s^2 2px^2 py^1 pz^1

Oxygen's largest shell is 2. So, like with carbon, count the electrons on the largest shell. You get 6.

There is a way easier way of interpreting this where you do not even have to write the orbital notation. I wish I can explain, but just know the periods and the group numbers.