Olympiad Test: Soil, Rocks & Minerals - 2 - Class 6 MCQ

Alluvial soil is deposited by rivers in plains and is very fertile, suitable for crops like rice and wheat.

Minerals are naturally occurring, inorganic substances with a definite chemical composition. Examples include iron, copper, and mica.

Graphite, a soft form of carbon, is used as the “lead” in pencils.

Diamond, a precious mineral, is used in jewelry due to its brilliance and hardness.

The reddish color of red soil comes from iron oxide content.

Clayey soil retains water and is therefore suitable for rice cultivation, which needs standing water.

Minerals cannot directly grow crops, though they improve soil fertility when processed. Minerals are widely used in construction, fuels, and medicines.

Diamond is the hardest known natural substance and is used for cutting, drilling, and polishing.

Ores are rocks from which minerals can be profitably extracted, such as bauxite (aluminum ore) and hematite (iron ore).

Soil is a natural resource that takes thousands of years to form but can be eroded quickly. Conserving it is necessary to maintain fertility and support agriculture.