Question

What is an alloy? An alloy usually has some property which makes it useful in a specific way. What is the special property of:
(a) duralumin?
(b) type metal?

Answer 1

An alloy is a uniform combination of two or more metals or a metal with a non-metal. Alloys usually have different properties from their constituent elements.
The special property of duralumin is as follows:
(a) Duralumin is an alloy of aluminium (also containing a small quantity of Cu, Mn and Mg). It has higher tensile strength than aluminium and is resistant to corrosion. Thus, it is used in making parts of automobiles, aircrafts, etc.

(b) Type metal is an alloy of lead, tin and antimony. It expands when solidified and can be easily form casts as compared to Pb, Sn and Sb (which do not form good casts).