What is an ion? Explain the types of ion with examples.

A charged species from either by the gain of electron or loose of the electron is known as an ion. 

Ions are of two types:

Cation and Anion

Cations are formed by loosing of electrons.

Example: 

Na+ is cation formed by loosing of an electron from Na atom.

Anions are formed by gaining electrons.

Example:

Cl- is anion formed by gaining an electron by the Cl atom.

The atoms which have charges like +ve and -ve is an ion. Ex. Na+ or Cl-. When in sol of NaCl current is passed at that time Na + ions move to the -ve electrode(cathode) and Cl- This moves to the positive electrode (anode) process is known as Electrolysis. 

How it becomes Na+? 

The atomic no of Na is 11 i.e. 1s², 2s²,2p⁶, 3s¹. As the last shell contains one unbalanced electron. Na(sodium) can easily give up this electron. As we know that no. of an electron is equal to the no. of protons. When Na releases 1 electron no of protons in the nucleus increases, hence Na becomes Na+.

An atom or molecule having a net charge (positive or negative) on it is called an Ion. Positively charged ion is called Cation, and negatively charged ion is called Anion. 

E.g., Sodium (Na) has 11 electrons in a neutral state, and by losing one electron, it forms a sodium cation (Na+), and Chlorine has 17 electrons in a neutral state. By gaining one electron, it forms chloride anion (cl-).

Other examples: Mg²⁺, Al³⁺, NO₃^-, and SO₄^2-.

An ion is a charged species; when placed in solution, it will have its ionic environment which is composed of solvent molecules directed by the opposite charge of that of ion.

It can be of two types:

1. Cation: Have a positive charge. Generally, metals exist as cations. Ex Mg2+, Sc3+.

2. Anion Have negative charge. Generally, p-block lighter element or non-metals exist as anions. Ex: F-, (SO4)2-