Question

explain that metals are good conductors of electricity with the help of and example

Answer 1

ex1:- iron is a metal :-
some time u touch your home light switches and when your hand wets and suddenly u get electric shock.........

Answer 2

A good conductor of electricity is any material that allows easy passage of electricity through it without much resistance. 
For example, copper is used for electricalwiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity.

Metals have these typical physical properties:

Lustrous (shiny)
Hard
High density (are heavy for their size)
High tensile strength (resist being stretched)
High melting and boiling points
Good conductors of heat and electricity

These properties make metals useful for many purposes. For example:

Iron is used to make cars and bridges because it is hard, with a high tensile strength

Copper is used to make electrical wiring because it is a good conductor of electricity