What is a Cation?

What is a cation? An atom contains electrons protons and neutrons. Every atom contains an equal number of negative electrons and positive protons. These protons and electrons balance charge in the atom and make it neutral. When an atom loses its neutrality on leaving or gaining an electron the following question arises.

Chemistry Strcure of atom

What is a Cation or Anion?

When an atom loses or gains electrons, we say atom changes into an ion. There are two types of Ion

A. Cation and

B. Anion

1. If an atom has less electron than normal it gets a positive charge.We call as cation . It is because the number of negative electrons becomes less than the number of positive protons.

2. If an atom has more electrons than normal atom then it gets a negative charge. We call as an anion.The reason is the number of negative electrons becomes more than the number of positive protons.


It is only the electrons which can transfer from one atom to another atom in the formation of an ion.

Why Atom lose electron

Atoms lose electrons to form a bond(molecule).They form a bond to achieve:

A. Minimum Energy  and

B.Maximum Stability.

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Examples of Cations?

A positively charged ion is also known as cation. A cation is formed by the loss of one or more electrons by an atom.

What is a Cation

For example, Magnesium loses its two electrons to form Magnesium ion which is cation. Therefore cation contains fewer electrons than the normal atom.

i. If an atom loses one electron, then cation has one positively charge.
ii.If an atom loses two electrons, the cation formed has two positively charges.
iii.if the atom loses three electrons, then cation has three positively charges.

It is usually not possible to remove more than three electrons. A very high energy required for this purpose.

Note: The electrons lost by a metal atom during the formation of the cation are accepted by a non-metal atom which then turns into the anion or Negative Ion.

What is a Cation

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