Statement I :
I. Very little hydrogen is produced when sulphuric acid is added to calcium.
Statement II :
II. The salt that is produced, calcium sulphate, is insoluble.

Statement I :
I. Limestone decomposes when it is heated in air.
Statement II :
II. Increase in the content of CO2 in the atmosphere in recent years is mainly due to the using of limestone in the manufacture of cement.

Statement I :
I. Glass is not considered as a true compound.
Statement II :
II. Glass does not have a definite melting point.

Statement I :
I. In the 19th century, India was the largest British colony.
Statement II :
II. India became a big market for British manufactured goods and a field of investment for foreign capital in the 19th century.

Statement I :
I. Doldrums is a calm belt between 5^o N and 5^o S of the equator.
Statement II :
II. The sun rays strike almost vertically over the equator throughout the year.

11. Statement I :
I. The process of decay and disintegration of rocks in situ is called weathering.
Statement II :
II. Weathering takes place both mechanically and chemically.