How can you determine electron cloud size?

Hint: Electron size is defined as a species that contains positive or negative charge. All the electron sizes either have more number of protons than electrons or more number of electrons that protons in their atomic structure. Positive charges are those that contain more number of protons than electrons and the negative charges are those that contain more number of electrons than protons.

Complete answer:
The electron sizes that contain positive charge are known as cations. For example, and so on. The electron sizes that contain negative charge are known as anions. For example, and so on. Electron size radius is defined as the distance from the nucleus of an ion to the electron cloud. The electron size of a cation will be smaller than that of the parent atom, because they lose its electrons while their nuclear charge remains the same. The remaining electrons are held tightly by the protons in the nucleus and therefore decrease the size of the cation.
An electron size is larger in size as compared to parent atoms. The reason behind this is when an atom gains an electron, and then there will be an increase in total number of electrons which creates more repulsion between the electrons and hence overshadows the net effective nuclear charge. The size of both the parent atom and ion will increase when the principal quantum increases. If there is an increase in the nuclear charge, then there will be a decrease in the electron size.

Note:
It is important to know that the electrostatic force of attraction, that is formed between a cation, which is positively charged and an anion, which is negatively charged, are the driving force behind the formation of electron size bonds. The electron size bond formed between the two oppositely charged electron size results in the formation of an electron size compound.