Question

Steel is made up of:
A.Copper and tin
B.Iron, carbon and chromium
C.Iron, carbon and tin
D.Iron, carbon and silicon

Answer 1

Alloys: Alloys are the metallic compounds formed by two or more metals or one metal with any other elements. For example: steel, bronze, brass, etc. They have high resistance towards rusting. So they are used widely. Examples of alloys are: steel, bronze, brass, etc.

Complete step by step answer:
Alloys can be classified into two categories: Substitution and interstitial alloys.
Properties of alloys:
They are less malleable i.e. can be hammered to thin wires.
They are less ductile i.e. they can be converted to thin sheets.
They are more corrosion protective i.e. in these compounds corrosion does not take place easily.
Few applications of alloys are:
Stainless steel is used for making wire such as cable.
Alloys of silver and gold are used to make jewellery as we cannot use $100\%$ gold to make jewellery because if we use $100\%$ gold to make jewellery then it will be too soft. So we will not be able to design it properly. So gold is added with some amount of copper or zinc to make it suitable for making jewellery.
Alloys are used as resistance elements which are used to control electric current.
Alloys which have high resistance towards corrosion are used in moisture rich places.
Steel is an alloy of iron and carbon. But if we only use these two elements then it will be more corrosive in nature. So to reduce the tendency of corrosive chromium is added in it. Hence steel is an alloy of iron, carbon and chromium.

So, the correct answer is Option B.

Note:
Bronze is an alloy of copper and tin in which the amount of copper is higher than that of the amount of tin used while brass is an alloy of copper and zinc. Coin silver is an alloy of silver and copper.