occurrence in nature

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 state i.e. in the form of com..

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 that element. For instance, flu..

Depending upon the shape and function, epithelial tissues are classified into different type..

Occurrence - 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 chloride. All the members of the group VII A are highly reactive, and they are not available in nature..

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..

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 al..

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 chloride. All the members of the group VII A are highly reactive, and they are not available in nature in the free state. It ..

The most abundant mineral of calcium is calcium carbonate. It occurs in nature in different forms, such as limestone, marble, chalk etc. Calcium carbonate occurs abundantly as dolomite, MgCO 3 .CaCO 3 , a mixture of calcium and magnesium carbonates. It is the chief constituent of shells ..

Methane occurs in: Natural gas Marshy areas where plant matter rots and decomposes. (paddy fields, stagnant ponds) Coal mines Bodies of termites (cellulose digesting insect) Intestines of ruminating animals (animals that chew the cud e.g., cows) Constituent of biogas..