Question

Give reason why:
 $ (a) $ Copper metal is used for making electrical wire
 $ (b) $ Gold and silver is used for making jewellery.

Answer 1

Hint: Metals have so many properties that they are used widely in any field, metals are used in making wires, jewelry, buildings, bridges etc. because they are strong and easy to shape, and have stable boiling and melting points.

Complete answer:
(a) Copper is used in a variety of applications, one of which is electrical wires. Some properties telling why copper is used in making electric wire:
High conductivity: Copper is a highly conductive metal. This means electricity can pass through it with greater ease, making it ideal for use in electrical wires.
High Ductility: Copper isn’t just conductive but also ductile. In other words, you can bend and flex copper without breaking it. The ductile property of copper allows electrical wires to bend and flex and still they can transmit electricity.
Thermal Resistance: Copper electrical wires are safer to use than wire made of most other conductive metal because they are resistant to heat.
 $ (b) $ Gold and silver are used for making jewelry because they are extremely unreactive metals, so unlike most metals it takes a long time to develop even a slight tarnish. This means that its bright color and shine stay for years and it doesn’t discolor in contact with moisture.
It is pretty easy to work with because it is soft, has a low melting point and is easy to create highly detailed designs. They are highly lustrous, malleable and ductile, which means they can be converted into thin wires easily.
Gold does not react with any acids and does not form any oxide. Therefore, gold is alloyed with other metals to make it stronger.

Note:
Not only gold and silver, platinum is also used in making jewellery, because platinum is rare and highly lustrous and resistant to corrosion, it is highly ductile and malleable. Gold is also an excellent conductor of electricity, but it will be very expensive to make wires out of gold, thus copper costs less than gold.