Who made the idea that as you go down the periodic table the atomic radius increases and the first ionization energy decreases?

The idea that as we go down the periodic table the atomic radius increases and first ionization energy decreases was given by Henry Moosely after he made some changes in the periodic table, the theory proposed by Mendeleev.

Explanation:

Both these trends were well explained and supported by genuine reasons. As we go down a group in periodic table, a new shell is added at each level, which increases the size and hence the radius of the atom and the size of atom increases which means the outermost shell is increasingly moving farther from the atom. Due to this fact, electrons experience less attractive force from the nucleus and electrons are easily removed, so the first ionization energy decreases.

The answer is b on plato.

Neither model is able to show the reactivity of potassium.