Difference Between Atom And Ion

Atom refers to the smallest unit of matter that contains equal number of electrons and protons. It is neutral by nature because of the equal number of protons and electrons. On the other hand, ion refers to molecule or atom having unequal number of protons or electrons. It may charge either positively or negatively. Molecules are the combination of atom and compounds are the combination of ion.

Difference Between Atom And Ion

The major dissimilarities or difference between atom and ion can be highlighted as follows:

1. Introduction

Atom: A smallest constituent of an element with same number of protons and electrons is known as atom.

Ion: Atom or molecule with unequal number of protons and electrons is known as ion.

2. Nature

Atom: It is stable in nature

Ion: It is unstable in nature

3. Protons And Electrons

Atom: There are equal number of protons and electrons

Ion: Number of protons and electrons are not equal 

4. Charged

Atom: It is neutrally charged

Ion: It is charged either positively or negatively

5. Chemical Reaction

Atom: It has important role in chemical reaction

Ion: It has no role in chemical reaction

6. Ionic Reaction

Atom: It has no role in ionic reaction

Ion: It has important role in ionic reaction

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Difference Between Atom And Molecule

7. Existence

Atom: It cannot exist independently

Ion: It can exist independently

8. Combination

Atom: Combination of atoms form molecules

Ion: Combination of ions form ionic bonds.

Atom Vs Ion (Comparison Chart)

Basis	Atom	Ion
Protons and electrons	Equal number	Unequal number
Nature	Stable	Unstable
Charged	Neutrally	Positively or negatively
Role in chemical reaction	Yes	No
Role in ionic reaction	No	Yes
Exist independently	No	Yes
Combination	Forms molecules	Forms ionic bonds

Distinction Between Atom And Ion In Short

- Atom is unstable and ion is stable by nature.

- Atom cannot exist independently. But independent existence of ion is possible.

- Atom does not play any role in ionic reaction but it has significant role in chemical reaction. Conversely, ion plays a significant role in ionic reaction but it doesn't have a role in chemical reaction.

- Atom is composed of same number of protons and electrons but ion consists of unequal number of protons and electrons.