00:02
Okay, so in this question, we are comparing the energies of electrons in different orbitals or suborbitals.
00:11
So when we're comparing 2s and 2p, they have the same principal quantum number, but they are different shapes.
00:21
So the electrons, we know usually, want to fill the s subshell first because it is the simplest shape and closest to the nucleus.
00:30
So, the electrons that are closer to the nucleus have a lower energy than the electrons that are further from the nucleus.
00:37
And there's not much of a difference in energies, like there is a difference, but there's not a massive difference between the electron energies in 2s and 2p.
00:46
But since the electrons in 2s are closer, they fill up for the 2s orbital will fill before the 2p orbital.
00:54
Thus, the 2s orbital has a lower energy.
00:57
Now let's look at 3p.
01:01
Versus 3d.
01:02
This is the exact same logic where we say the same principle quantum number.
01:09
So now we need to look at the shapes...