cations and anions [ENDORSED]

[Brenda Tran 3C]

Hi! Can someone explain to me why cations are smaller than their parent atoms and anions are larger? It was probably mentioned in the lecture but I couldn't hear due to the static. :-) Thanks!

[Jamie Lin 1K]

Cations are smaller than their parent atoms because cations have less electrons than their parent atoms, meaning cations have a greater effective nuclear charge, which decreases the atomic radius. Anions are larger than their parent atoms because anions have more electrons than their parent atoms, which means a greater amount of electron electron repulsions and/or more shells of electrons, which would enlarge the atomic radius.

[Meg Yuan 1G]

Cations are smaller than their parent atoms because they lose their valence electrons, thus there are no longer electrons in the outermost shell. In addition, there is less electron-electron repulsion but the nucleus’s charge remains the same so the electrons are pulled more tightly towards nucleus. Anions are larger than their parent atoms because they gain atoms in their valence shell, which increases electron-electron repulsion. Also, the charge of the nucleus remains the same but more electrons means the electrons in an anion are less tightly held.

[Hannah Carsey 1B]

In general, anions are larger than the corresponding neutral atom, since adding electrons increases the number of electron-electron repulsion interactions that take place. Cations are smaller than the corresponding neutral atoms, since the valence electrons, which are furthest away from the nucleus, are lost.

[905756606]

Cations are formed when atoms loose electrons. This occurs commonly in metals as they have low ionisation energy and can lose their valence electrons to achieve a more stable noble-gas configuration. Losing their valence electrons means that the principal quantum number, n, also decreases by one as the outer shell is lost. Not only does this cause the atomic radius to decrease, but since the number of protons doesn't change, there is a greater effective nuclear charge and electrostatic force of attraction between the valence electrons of the cation and its nucleus.

[Cassidy Chiong 2J]

Hi!

Cations are smaller than their parent atoms because they have the same number of protons as their parent atoms, but fewer electrons. With fewer electrons, there is less electron-electron repulsion, resulting in a smaller electron cloud. Same goes for anions; they have the same number of protons as their parent atoms, but more electrons. Thus, they experience more electron-electron repulsion, resulting in a larger electron cloud.

You could even think of anions have more "stuff" inside the atom and cations having less "stuff" inside the atom.

[Caitlyn Lo 2F]

Cations are smaller than their parent atom because cations have one less electron than their parent atom which means there are more protons than electrons, causing their to be a greater positive charge in the atom causing the outer electrons to be brought in closer to the nucleus which causes the atom to become smaller. Anions are the opposite in that they have one more electron than protons in the atom and because there is more negative charge than positive charge, the electrons are not as attracted to the nucleus causing the atom to be bigger than the parent atom.

[Madison Nguyen 3L]

Cations are smaller due to the "positive charge," in which one electron is removed, and thus, it has one less electron than its parent atom; this means that the atom has a greater positive charge due to protons > electrons, attracting the valence electrons and bringing them closer to the nucleus. In turn, this makes the atom far smaller in size.
Inversely, anions are larger due to its "negative charge," in which it has more electrons than protons in that it has one more electron than its parent atom, and thus, the atom ascertains a negative charge. The electrons are therefore not as attracted to the nucleus due to the greater negative charge, causing the atom to be bigger than the parent atom and increase in size. This is opposite of how a cation creates a positive charge and is more attracted to the nucleus due to the removal of electrons.

[Maggie Clark]

Cations are smaller because they have less electrons than the ground state element. Anions are larger because they have more electrons.

[Alex Luong 3H]

Like many others have said, cations are smaller because they have less electrons, and therefore less shielding which results into the nucleus (positive) pulling the electrons closer, resulting in a smaller radius. The opposite could be said for anions, which have an extra electron, increasing electron shielding and therefore the atom's radius. Sorry about the run-on sentences.

[EvaHeinrichs3C]

What is the relevance of cations and anions? Like what are they used for?

[EvaHeinrichs3C]

Additionally, WHEN would we use cations and anions?

[EvaHeinrichs3C]

What is the difference between cations and anions?