Chemistry

1.The mineral containing both magnesium and calcium is

magnesite calcite carnallite dolomite

2.The most extensive, commercially useful source of thorium as monazite sand occurs in India at

Orissa coast Travancore coast West Bengal coast Gujarat coast

3.The main active constituent of tea and coffee is

nicotine chlorophyll caffeine aspirin

4.The hardest form of carbon is

coke graphite diamond charcoal

5.The hottest part of the gas flame is known as

luminous zone dark zone blue zone non-luminous zone