occurrence of elements

Occurrence of Elements in Nature - A large number of elements occur inside or around the earth. Less reactive elements, like platinum, gold, nitrogen, oxygen etc., occur in free (native) state. Chemically active elements always occur in the combined..

A large number of elements occur inside or around the earth. Less reactive elements, like platinum, gold, nitrogen, oxygen etc., occur in free (native) state. Chemically active elements always occur in the combined state i.e. in the form of compounds containing t..

Occurrence - Astatine the last member of halogen family is a radioactive element with a very short life. All other halogens are abundant in nature in the combined state. The very high electronegativities of halogens make them very reactive and hence, they are not found in free s..

Chlorine belongs to the 'halogen' family. All the elements of this family are non-metals. They exhibit similar properties and they all form salts similar to sodium chlorid..

Astatine the last member of halogen family is a radioactive element with a very short life. All other halogens are abundant in nature in the combined state. The very high electronegativities of halogens make them very reactive and hence, they are not found in free stat..

Noble gases always occur in free state because of their inert nature. All the noble gases, except radon are present in air in small amounts. The relative abundance of the noble gases in air is = 1%. Helium is present in natural gas up to the extent of 10 per cent. It is also present in small ..

Astatine the last member of halogen family is a radioactive element with a very short life. All other halogens are abundant in nature in the combined state. The very high electronegativities of halogens make them very reactive and hence, they are not found in free state. In the combined s..

Alkali and alkaline Earth metals are the most violently active of all the metals. These occur in the combined form with halide, sulphate, carbonate, silicate ions, etc. and are not found in the free state in nature, as these are readily oxidized. A number of alkali and alkaline Earth metals are fo..

Hydrogen is the most abundant element in the universe. About half the mass of sun and stars is due to hydrogen. Jupiter and Saturn planets consist mainly of hydrogen. It is common on earth in water, coal, petroleum, clay, animal and vegetable matter that constitutes 0.9% by weight of Eart..

Occurrence and Uses - Aluminium is the third most abundant element (8.3% by weight) in the earth's crust after oxygen (45.5%) and silicon (25.7%). The important minerals of aluminium are: a) Bauxite, AlO x (OH) 3 - 2 x (0 < x <1) b) Cryolite, Na 3 AlF 6 c) Orthoclase, KAlS..