Answerthe following questions in about 30 words.
(i) Distinguishbetween the following in not more than 30 words.
(a) Ferrousand non-ferrous minerals
(b) Conventionaland non-conventional sources of energy.
(ii) Whatis a mineral?
(iii) Howare minerals formed in igneous and metamorphic rocks?
(iv) Whydo we need to conserve mineral resources?
(i) (a) Minerals containing iron are called ferrous minerals, e.g., iron ore and manganese. Minerals which do not contain iron are called non-ferrous minerals, e.g., bauxite, lead and gold.
(b) Conventional sources of energy are generally exhaustible and polluting, e.g., firewood, coal and petroleum. Non conventional sources of energy are usually inexhaustible and non-polluting, e.g., solar, wind, tidal and atomic energy.
(ii) A mineral is a homogeneous, naturally occurring substance with a definable interior structure. Minerals are formed by a combination of elements, and the mining of some minerals is very profitable.
(iii) In igneous and metamorphic rocks, molten/liquid and gaseous minerals are forced upwards into the cracks. They then solidify and form veins or lodes.
(iv) Mineral resources need to be conserved because they are limited. It takes billions of years for them to be replenished in nature. Continued extraction of ores leads to increasing costs of extraction and a decrease in quality as well as quantity.