Periodicity when elements are diagonal to each other

[arielle_cunanan3K]

Hi, so when two elements are diagonal to each other on the periodic table like C and P or O and P. Which trend will it follow? Since one element will be higher in a group and to the right in a period and the other element will be vice versa. Which one would have a higher ionization energy and/or large atomic radius?

[Dana Sorensen 1C]

For atomic radius, those that are below in period are always bigger since there will be more shells, the radius decreasing across a period only applies to each period within itself and is still a smaller amount compared to the increase in radius through a group. For ionization energy, it increases up and to the right, so in a upper right diagonal direction. Hope this helps!

[Tammy Shen 2L]

It depends on which elements you're looking at. Even though the atomic radius trend will decrease left to right and increase top to bottom, the change in radius from top to bottom is much larger than left to right. Changes left to right in atomic radius only depends on the attraction between protons and electrons in the same shell: the more protons there are, the greater the pull, and thus atomic radius decreases. However, atomic radius across periods have greater change due to shielding.