Atoms cannot exist independently. 

So in order to exist stably in nature, they combine to form molecules.

 

What is a Molecule?

A group of atoms chemically bonded together is called Molecule.

 

What are Different Types of Molecules?

Molecules are of 2 types

  • Molecule of Single Element
  • Molecule of Compound

Different Types of Molecules-Teachoo-01.jpg

Molecules of Single Element

They contain 2 or more atoms of the same type chemically bound together

 

Examples

  • Oxygen molecule O 2 has 2 atoms of oxygen ato
  • Ozone molecule O 3 has 3 atoms of oxygen atom

 

What is a Molecule?

A group of atoms chemically bonded together is called Molecule.

 

What are Different Types of Molecules?

Molecules are of 2 types

  • Molecule of Single Element
  • Molecule of Compound

Molecules of Single Element

They contain 2 or more atoms of the same type chemically bound together

Examples

  • Oxygen molecule O2 has 2 atoms of oxygen atom
  • Ozone molecule O3 has 3 atoms of oxygen atom

 

What is a Molecule?

A group of atoms chemically bonded together is called Molecule.

 

 

What is atomicity?

Number of atoms in a molecule of element is called atomicity

  • Some atoms are Monoatomic
    They have 1 atom which exists independently
    Example-Argon (Ar), Helium (He)

 

  • Some atoms are Diatomic
    They have 2 atoms chemically combined together
    Example - Oxygen (O2 ), Hydrogen(H2), Nitrogen(N2), Chlorine(Cl2)

 

  • Some atoms are Tetra-atomic
    They have 4 atoms chemically combined together
    Example-Phosphorus(P4)
  • Some atoms are Polyatomic
    They have many atoms chemically combined together
    Example- Sulphur(S8) has 8 atoms chemically combined together

Molecules of single element and their atomicity-Teachoo-01.jpg

What is a Molecule?

A group of atoms chemically bonded together is called Molecule.

Molecules of Compounds

Some compounds contain more than 1 type of element.

These elements are combined in fixed proportion.

Example

  1. H 2 O - It contains 2 atoms of Hydrogen chemically combined with 1 atom of Oxygen.

  2. CO 2 - It contains 1 atom of Carbon combined with 2 atoms of Oxygen

Molecules of Compounds-fullWidth-01.jpg

Example -

In text Question -

NCERT Question -

  1. Class 9
  2. Chapter 3 Class 9 - Atoms And Molecules (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo