CHEMISTRY COMMUNITY

Why are cations smaller than their parent atoms?

Cations are smaller than their parent atoms because they have less electrons. Cations are positively charged ions, so when they lose their electrons, the remaining electrons move closer to the nucleus, and the size of the cation is reduced.

Cations are smaller because these atoms have a positive charge on their central nucleus, which means that there are more protons than electrons. The positive charge pulls the electrons closer to the nucleus than if there were to be a neutral nucleus. This greater attraction leads to a smaller atomic radius.

Cations are smaller than their parent atoms because they are formed by a loss of electrons from the parent atom, while their nuclear charge stays the same. This makes the electrons stay closer to the nucleus, and therefore make the cation smaller than the parent atom.

Since there are fewer electrons but the same number of protons, the protons have a greater pull on the fewer number of electrons, therefore those electrons are drawn in closer to the nucleus, making the size of the cation smaller.

On the other hand, anions are bigger than their parent atoms because (as indicated by their negative charge) they gained electrons.

405404782 Gabriel Rigole 4F wrote:Why are cations smaller than their parent atoms?

The way that my PLF told me to remember was that Cat-ions (paw-sitive) means that they're losing an electron (bc it's positive) and the Anion is like onion crying because it's gaining an electron. If it's losing an electron that means it's smaller than its parent whereas if it's gaining one then it's bigger.

Cations are smaller than their parents atoms because they have less electrons. Similarly, anions are larger than their parent atoms, because they have more electrons.

Cations lose an electron, which means that their atomic radius is smaller. They oftentimes resemble the element before that which are smaller.