Difference Between Atom and Ion

Atom

An atom is called the fundamental unit of matter. It cannot be further divided into smaller parts and comprises neutrons, electrons, and protons. Chemical reactions take place because of the reactions between atoms. The amalgamation of atoms with each other forms a molecule. The number of protons and the number of electrons equal each other. Independent life may or may not be achievable inside an aqueous solution. Protons and neutrons form the nucleus in an atom. The electrons surround the nucleus and are placed on various levels of orbitals.
Example: H, N, O, Fe

Properties

An atom is called the fundamental unit of matter. It cannot be further divided into smaller parts and comprises neutrons, electrons, and protons. Chemical reactions take place because of the reactions between atoms. The amalgamation of atoms with each other forms a molecule. The number of protons and the number of electrons equal each other. Independent life may or may not be achievable inside an aqueous solution. Protons and neutrons form the nucleus in an atom. The electrons surround the nucleus and are placed on various levels of orbitals.
Example: H, N, O, Fe

• Nuclear properties: Two atoms that share the same proton number are a part of a similar chemical element. Atoms that have the same proton number but the neutron number is different, then it is called isotopes. Example: Hydrogen atoms contain one number of the proton but their isotope has no number of neutrons.
• Mass: The maximum mass of every atom is a combination of neutrons as well as protons. The total number of both the protons and neutrons present is termed as mass number. The mass number always has to be dimensionless and a positive whole integer. The unit expressed for the mass of an atom is daltons (Da).
• Shape and size: Atoms do not possess a well-designed boundary, hence their dimensions are defined as atomic radius. It is measured in terms of its distance where the cluster of electrons expands from its own nucleus. The smallest recorded atom is helium. It has a radius of 32 pm.

Ion

Ions are formed because of the inequality of electrons and protons in an atom. Ions are usually the charged particles. The ions can be either positively charged or negatively charged. An atom is considered to be an ion if it is electrically charged. An atom is called an anion if the number of electrons is greater than the number of protons. And an atom is considered a cation when the number of protons is greater than the number of electrons. It is independently feasible in a solution. An ion is generated when an atom gains or loses electrons.
Example: Na+, H+, O2-

Characteristics

When ions are in their gaseous state, they are highly reactive. It reacts rapidly with those ions that have opposite charges just in order to result in ionic salts or neutral molecules. When solvents and salts react with one another, ions are given out in the solid as well as a liquid state to give solvated ions. The electric charge that is present on a proton is equivalent to the amount of charge that an electron carries. An ion is of two kinds
1. Anion - The number of electrons is more than the number of protons. It is denoted by the negative sign.
2. Cation - It is denoted by a positive sign. The number of electrons is lesser than protons.

Basic difference between an atom and an ion
 

Summary

Atoms are the fundamental unit of every matter that cannot be broken down further. It consists of electrons, protons, and neutrons. When an atom is electrically charged, it gives rise to ions. The number of electrons and protons in an ion are unequal and hence the ions are unstable in their nature.