Ionic radius concept question

[Irene Kang 3F]

Why does it matter that the cations are smaller and the anions are larger than the parent atoms for the ionic radii of atoms?

[Kaitlyn Bateman 1L]

HI! Because cations have less electrons, they are smaller. Vice versa: anions have more electrons, so they are larger.

[Lawrence Tran 2H]

As for why we learn about ionic radii, I think it's suppose to help us understand ionic properties when ions interact with each other and other particles, such as in salts.

[Aanya Pramanik 1C]

I think this could help with understanding ionic radius trends because metals that form cations will have smaller ionic radii than nonmetal anions.

[LavieTran2B]

Hi,

It helps to know this because cations being smaller than parent atoms show that their ionic radius is going to be smaller due to the tighter core and electrons being closer to the nucleus. Whereas an anion, since it's larger than the parent atom shows that there are more electrons in the valence shell, creating a bigger radius.

[Emily Wan 1l]

Cations have a smaller ionic radius because after losing an electron, the remaining electrons are pulled more closely to the nucleus. Anions have a larger ionic radius because after gaining an electron, there is greater repulsion between electrons.

[Claire Kim 1F]

Why does it matter that the cations are smaller and the anions are larger than the parent atoms for the ionic radii of atoms?

It's just something nice to keep in mind seeing that cations lose an electron and anions gain an electron. Knowing this, cations have less electrons compared to anions which is why cations are smaller than the parent atoms and anions are larger than the parent atoms.

[Natalie Flores 1F]

Hi! Since cations have less electrons they are smaller and hence have a smaller ionic radius and vice versa, anions have more electrons so they are larger and have a larger ionic radius. The way I remember it is cations has a "t" in it which looks like a plus sign meaning they are positive (have less electrons) so the electrons are going to be pulled closer to the nucleus thus creating a smaller radius. For anions I think of onions (similar spelling haha) and I have a negative connotation with onions so I always remember anions are negative meaning they have more electrons which means the radius is going to be bigger. I hope this clarifies and helps you remember!