CHROMATOGRAPHY

Chromatography is a modern method proposed by Tswett in 1903. This method is based on the difference in the rates at which the components of a mixture are adsorbed on a suitable adsorbent. This method has been used to separate o and p- nitrophenol, to separate blue and red dyes, to separate plant pigments and other natural products.

DISCOVERY OF ELECTRON

Electron was discovered by J.J Thomson in 1897. When an electric charge at high voltage is passed through a gas at low pressure, a stream of rays is emitted from the cathode surface. These are called cathode rays.

DRAWBACKS OF DALTON ATOMIC THEORY

- It does not explain why atoms of different elements differ in their masses, valencies, etc.
- It does not explain the existence of isotopes and isobars.
- It does not explain the reason for difference in atoms of different elements.
- Discovery of electron, proton, and neutron discarded the individual nature of atom proposed by Dalton.

DALTON'S ATOMIC THEORY

The first definite theory about the structure of the matter was put forward by John Dalton in 1890.
Its main postulates are;
- All matter is made up of very small particles known as atoms.
- Atom neither be created nor be destroyed, it is the smallest particle that take part in a chemical reaction.
- All atoms of an element are alike and of different elements are different.
- Atoms of different elements have different masses and chemical properties.
- Atoms combine together in the ratio of small whole numbers.

HISTORY OF PLANNING IN INDIA

1.) First attempt to initiate economic planning in India was made by Sir M Vishveshvarayya, a noted engineer and politician, in 1934 through his book 'PLANNED ECONOMY FOR INDIA".

2.) In 1938, national planning commission was set up under the chairmanship of Jawahar lal nehru by the Indian National Congress. Its recommendations could not be implemented because of the beginning of the world war II and changes in the the Indian political situations.

3.) In 1944, 'Bombay Plan' was presented by 8 leading industrialists of Bombay. It was drafted by GD Birla and JRD Tata.

4.) In 1944, 'Gandhian Plan' was given by Sarojini Naidu Agarwal.

5.) In 1945, 'People's Plan' was given by MN Roy.

6.) In 1950, 'Sarvodaya Plan' was given by JP Narayan. A few points of this plan were accepted by the government.

BROAD SECTORS OF INDIAN ECONOMY

1. PRIMARY SECTOR
    Agriculture, forestry, fishing.

2. SECONDARY SECTOR
    Mining, Manufacturing, electricity gas and water supply, construction.

3. TERTIARY SECTOR
    Business, transport, telecommunication, banking, insurance, real estate, community and personnel services.

Important Facts about Some Metals (PART-II)

1. Chromium trioxide is known as chromic acid.
2. Nichrome wire is used in electric heaters[Ni, Cr, Fe].
3. Generally transition metals and their compounds are coloured.
4. Zeolite is used to remove hardness of water.
5. In cytochrome iron[Fe] is present.
6. Selenium metal is used in photo electric cell.
7. Gallium metal is liquid at room temperature.
8. Palladium metal is used in aeroplane.
9. Radium extracted from pitch blende.
10. World famous Eiffel Tower has steel and cement base.