CHEMISTRY [1 Mark Question Answer]

Sedimentary rocks are also called as secondary or derived rocks as the material (clay or sand, etc.) they are formed from is derived from other rocks (igenous/primary).

Igneous rocks, sedimentary rocks and metamorphic rocks.

Chemical name of Plaster of Paris is calcium sulphate hemihydrate.
Use – It is used for plastering fractured bones, making casts for statues, decorative work on walls and ceilings.

Chemical name of lime is calcium oxide.
Use – It is used in agriculture to neutralize acidic soil. Is also used for making glass, cement and for whitewashing.

Chemical name of rock salt is sodium chloride.
Use – It is used in cooking, to preserve pickles, meat, etc. Is also used to manufacture baking powder, washing soda, etc.

Fossil fuels : Fossil fuels are the fuels which are formed by the decay and decomposition of the remains of dead plants and animals, buried under the earth millions of years ago. Coal, petroleum and natural gas are known as fossil fuels.

Fossil : Fossils are the remains of prehistoric plants and animals buried under the earth millions of years ago.

Gemstone: A gemstone (or gem) is a piece of mineral which is used to make jewellery.

Ore : The minerals from which metals can be extracted conveniently and economically are called as ores.

Mineral : A mineral is a naturally occuring substance which contains elements or their compounds.

Chemical name of rock salt – Sodium chloride

Chemical name of galena – Lead sulphide

A mineral containing copper carbonate – Malachite

An ore of silver – Argentite (silver sulphide)

Chemical name – Mercury sulphide
Metal extracted – Mercury

Chemical name – Lead sulphide
Metal extracted – Lead

Chemical name – Hydrated aluminium oxide
Metal extracted – Aluminium

Chemical name – Iron oxide
Metal extracted – Iron

Pumice – Igneous rock

Gneiss – Metamorphic rock

Schist – Metamorphic rock

Basalt – Igneous rock

Chromium

Petroleum and coal

Lime (Quicklime)

Copper

Basalt (an igneous rock) and shale (a sedimentary rock)

Sandstone, limestone, coal

Granite, pumice, basalt

The solid crust of rocks that form the surface of the earth is called lithosphere.