Ans. 1. Iron is a widely used metal but if it used in the pure form, it may rust. 2. When a small amount of carbon (varying from 0.1% to 1.5% )is mixed with iron, we get an alloy called steel.
3. This alloy of iron is hard and strong and is used for making nails, screw, bridges, railway lines, ships, construction of buildings, vehicles. 4. An important property of alloy is that they resist corrosion.
So, iron articles rust readily whereas steel which is also made of iron will not undergo corrosion.
An alloy is a homogeneous mixture of two or more metals( or a metal and small amount of non-metal). If iron metal is alloyed with other metals like chromium and nickel, we get stainless steel that does not rust at all.