Question

How does the second row on the periodic table reflect the subshells of the second shell

Answer 1

The second row of the periodic table corresponds to the n=2 energy level. This means you have l=1 and l=0 as possible subshells, with the first two columns corresponding to the spin up and spin down electrons in the l=0 (also known as the s-orbital) and then there will be a leap to the other side where there are 6 columns. These columns are your l=1 subshells (also known as p-orbitals) and there are three of them, each corresponding to m=-1, m=0, and m=1. These three of these orbitals pretty much look the same, but they're on the x-axis, y-axis, and z-axis. Each of these orbitals holds 2 electrons, one spin up and the other spin down, and so that's literally why there are 6 columns here, one for each of these two electrons in each of the 3 p-orbitals.