5. A molecule is the smallest particle of a pure
substance which can exist independently.
6. WHAT IS PURE SUBSTANCE ?
Element
Atomic Elements
Na, Li, Ca, K, Fe
Molecular Elements
O2, Cl2, O3
Compound
Molecular Compound
H2SO4, CO2, C6H12O6, C6H6, CH4
Ionic Compounds
NaCl, NaBr, KCl, NaF
9. Why Molecule Exists Independently?
Molecule is formed by the combination of atoms
Atom forms bond to get stability
Molecule is stable specie because it is formed by the combination of
atoms
Molecule exist independently, because it is formed by the unstable
atoms which are now stable
11. ATOMICITY
The number of atoms present is a molecule is called atomicity
Examples
SUBSTANCE MOLECULE ATOMICITY
Carbon Dioxide CO2 3
Sucrose C12H22O11 45
Methane CH4 5
Sulphuric Acid H2SO4 7
Water H2O 3
Ethyl Alcohol C2H5OH 9
12. TYPES OF MOLECULE ON THE BASIS OF
ATOMICITY
Mono-atomic Molecule
The molecule which contain only atom.
Examples : Noble Gases ( He, Ne, Ar, Kr, Xe and Rn)
Poly-atomic Molecule
The molecule which contain two or more, same or different kinds of atoms
Examples : CO, CO2, H2SO4, C12H22O11, C2H5OH, H2O, CH4
13. TYPES OF MOLECULE ON THE BASIS
OF NATURE
Homo-atomic Molecule
The molecule which are made up of same or one kind of atoms.
Examples : He, Cl2, O3, P4, S8
Hetero-atomic Molecule
The molecule which are made up of different kinds of atoms
Examples : HCl, NH3, H2SO4,C6H12O6
.
14. TYPES OF MOLECULE ON THE BASIS
OF SIZE
Micro-molecules
They are small in size
They are simple molecule
They exist as monomer
Examples
CO2, H2O, CH4
Macro-molecules
They are large in size
They have large no. of atoms
They are exist as polymer
Examples
Haemoglobin, Starch, Cellulose
Chlorophyll
16. What is Haemoglobin
It is a blood protein
It carries oxygen from lungs and transport to the all parts of body
Each molecule of hemoglobin is made up of 10000 atoms
It is made up of Carbon, Hydrogen, Nitrogen, Oxygen and Iron
It is 68000 times heavier than the hydrogen atom