Advertisement Remove all ads

Concept of an Ion

Advertisement Remove all ads

Topics

notes

Compounds composed of metals and nonmetals contain charged species. The charged species are known as ions. An ion is a charged particle and can be negatively or positively charged. A negatively charged ion is called an ‘anion’ and the positively charged ion, a ‘cation’. Take, for example, sodium chloride (NaCl). Its constituent particles are positively charged sodium ions (Na+) and negatively charged chloride ions (Cl– ). Ions may consist of a single charged atom or a group of atoms that have a net charge on them. A group of atoms carrying a charge is known as a polyatomic ion.

(i) Cation: It is positively charged ion and is formed by the loss of electron from an atom e.g. H+, Na+, Ca2+, Al3+, NH4+ etc.
(ii) Anion: It is negatively charged ion and is formed by the gain of electrons by an atom, e.g. Cl–, O2-, C–, F–, CO32- PO43- etc.

Some ionic compounds :

Ionic Compound

Constituting Elements

Ratio by Mass

Calcium oxide

Calcium and oxygen

5:2

Magnesium sulphide

Magnesium and sulphur

3:4

Sodium chloride

Sodium and chlorine

23:35.5

notes

Concept of an Ion:

The charged species are known as ions. A negatively charged ion is called an 'anion' and the positively charged ion, a 'cation'.

A group of atoms carrying a charge is known as a polyatomic ion.

Anions Cl-, Br-, O2-, N3-
Cations Na+, K+, Cu+, Al3+
Polyatomic ions `"""NH"_4^+, "OH"^–, """HCO"_3^-, "PO"_4^3–`
If you would like to contribute notes or other learning material, please submit them using the button below.
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×