[sd79812]

 Why is the slope in order of smallest to 1. largest main group (1-2), 2. transition metals, 3. main groups 13-18?

[Babcock_Hall]

What are your thoughts?

[sd79812]

Because of the octest rule?

Guess: The only factors at play here are the nuclear charge which without slater's rules we only use a Z_eff estimate play a constant rate increasing effect going across the column left to right.

If the atomic radius isn't dropping as heavily as atomic number increases across a period, the only possibility is the shielding is increasing across the period. But that's a contradiction because you inner shell isn't changing across the same period.

[sd79812]

What are your thoughts?

Going from Neon to Lithium, the atomic radius increases sharply because you introduce a electron shell. Previously the effect of shielding on Neon acted to the maximum effect, when you add a new shell, there's a new shell to act the shielding effect on, so you have two factors going from Neon to Lithium that explain that has the highest atomic radius within that period of Lithium. In subsueqent increases of atomic number starting from lithium, you increase nuclear charge which drops the atomic radius, the shielding factor remains constant across a period because the inner shell doesn't change, and I have no idea how to explain azimuthal effect (adding the p-orbital) yet the green dots have a lower absolute value slope than that of the purple dots when talking about iso-lithium period.