Why is gold platinum and silver are called noble metals?

Answer 1

They are not called alloys, these 5 metals are elements. An alloy is a metal which consists chemically of 2 or more different metals.

Gold, silver, copper, zinc, and nickel are often alloyed with other metals to improve upon the physical characteristics of the pure metal. Pure gold, for example, is soft and will be damaged quickly when used as coinage. It is much more durable when it is alloyed with silver. All metals used in manufacturing coins are alloys, but are referred to by the name of the main element in the alloy.

on there own they're too soft for many uses so they are mixed together to make them harder

Answer 2

they are alloys because they are metals made up of mixtures of other substances, not pure elements like iron. Steel is made up of mainly iron and carbon; bronze is made up of mainly copper, and usually a bit of tin but often other elements like phosphorus.

Answer 3

The British One Pound coin is made from 70% copper, 24.5% zinc and 5.5% nickel.

As far as coins go, the One Pound coin is a relatively high value general circulation coin and the alloy of these metals in these percentages make a gold coloured hard wearing, durable coin that is resistant to corrosion and is cheap to make.

Answer 4

To get the properties we want for specific applications.

Answer 5

These metals (especially platinum and gold) are less chemically reactive.