Ionic Radii

[Zoya Mulji 1K]

Why are anions much bigger than their parent atoms/ why are cations much smaller?

[Jainam Shah 4I]

Anions are ions that have gained an electron from the ground state. The number of protons stay the same, but the electrons increase. As a result the nuclear charge decreases and the electrons are not as tightly bound to the nucleus as before, thus increasing the ionic radii. For cations electrons are lost so we have the same nuclear charge but the electrons are more tightly bound to the nucleus reducing the ionic radii.

[Ziyan Wang 3J]

Cations are smaller because it reduces the energy level of valence electron by 1.

Anions are bigger because the repulsion force between electrons pushes electron outward.

[BCaballero_4F]

Anions are bigger because an electron is added. Cations are smaller because a valence electron is lost.

[AKatukota]

Anions gained an electron, therefore the radius is larger than that of the parent atom. If an atom loses an electron, it is a cation, and has a smaller radius. Hope this helps! :)

[Mitchell Koss 4G]

Even though an electron is negative, it still increases the size of the atom.

[Jorge Ramirez_4H]

What's the difference between ionic and atomic radii?

[alicechien_4F]

Ionic radii is the radius between two ions that are ionically bonded (ex: NaCl). Atomic radius is the radius between two neutral atoms. Hope this helps!

[Vincent Leong 2B]

The more electrons you have in an atom, the more negative charges you will have and it will result in more negative to negative interactions. If you think of a generic bar magnet, opposite charges (+/-) attract while similar charges (-/-) repel. The same applies to these anions. The more of a negative charge you have, the more e- REPULSIONS you'll have (aka shielding) and thus the radii will increase because more electrons will push the other electrons further from the nucleus.

[Catherine Daye 1L]

Anions are larger because they add another electron, creating more electron-electron repulsion between the valence shell electrons and the electrons in the shell below it (increasing distance between the shells). Cations are smaller because they remove an electron, decreasing the amount of electron-electron repulsion between shells.

[705379941]

anions gain an electron, so that can add an n, which makes the radius larger. Cations lose an electron, so that can take away an n, making the radius smaller