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Science

Atoms and Molecules

MOLECULE : -

A molecule is the smallest particle of a substance of independent existence. A molecule is composed of two or more atoms, its constituent atoms are chemically bonded together.

MOLECULAR FORMULA : -

The actual number of the constituent atoms in a molecule of a substance is called its molecular formula.

CLASSIFACTION OF MOLECULES : -

The atoms bonded together in a molecule may be of the same type or of different types.

1. Molecules of elements

2. Molecules of compounds

MOLECULES OF ELEMENTS : -

A molecule of an element is composed of two or more than two similar type of atoms.

ATOMICITY : -

The number of atoms bonded in a molecule of an element is called its atomicity.

CLASSIFICATION OF MOLECULES OF ELEMENTS BY ATOMICITY : -

The number of atoms in a molecule the elements are classified as monatomic, diatomic, diatomic and polyatomic.

MONATOMIC MOLECULES OF ELEMENTS : -

The noble gases exist in the atomic form and are stable, it’s called monatomic molecules.

EXAMPLE : -

Helium (He),

Neon (Ne),

Argon (Ar),

krypton (Kr),

Xenon (Xe),

Radon (Rn)

DIATOMIC MOLECULES OF ELEMENTS : -

A molecule containing two atoms is called a diatomic molecule. The atomicity of each diatomic molecule is 2.

EXAMPLE : -

Hydrogen (H₂),

Oxygen (O₂),

Nitrogen (N₂),

Fluorine (F₂),

Chlorine (Cl₂),

Bromine (Br₂)

TRIATOMIC MOLECULES OF ELEMENTS : -

A molecule containing three atoms is called a triatomic molecule.

EXAMPLE : -

Ozone (O₃)

POLYATOMIC MOLECULES OF ELEMENTS : -

The molecules containing four or more atoms of the same element are called polyatomic molecules.

EXAMPLE : -

Phosphorus (P₄)

Sulphur (S₈)

Boron (B₁₂)

Fullerene (C₆₀)

MOLECULES OF COMPOUNDS : -

A molecule of compound is composed of two or more atoms of different elements in definite proportions and chemically bonded.

COMPOUND	FORMULA	TYPE	ATOMICITY
Hydrogen chloride	HCl	Diatomic	2
Carbon dioxide	CO2	Triatomic	3
Ammonia	NH3	Tetratomic	4
Methane	CH4	Pentatonic	5
Methanol	H3OH	Hex atomic	6

 

Submitted By Mr. Ajay Kumar
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