explain the relatiomship between the relative size of an ion to its atom and the charge of the ion?

Answer 1

In general, adding electrons in an atom (thereby forming an anion) increases its size; while removing electons (forming cation) reduces its size.

For example, when an oxygen atom (O) gains electrons to become an oxide ion (O2-), its size dramatically increases due to additional electron-electron repulsion in the n=2 valence shell.

On the other hand, when a potassium atom (K) loses an electron to form a potassium ion (K+), its size dramatically decreases since there are no longer occupants in the n=3 shell.

The rule, when comparing atomic and ionic radii, is this:

cation < neutral atom < anion

Answer 2

An atom that has lost one or more electrons is positively charged. It is also smaller than a neutral atom because it has lost electrons. A positively charged ion is also called a cation.
An atom that has gained one or more electrons is negatively charged. It is also larger because it has extra electrons. A negative ion is also called an anion.

Answer 3

If the ion has -ive sign it shows that atom has gain one or more electron as a result electron charge increases with respect of proton and size of ion also increases
if an ion has +ive sign it shows it has loose one or more electrons eventually the electron charge decreases with respect of proton and proton attract electrons more efficiently and thus size of ion decreases