Question

What do you mean by noble metals?

Answer 1

Hint: Elements: The substance which is made up of only one kind of substance is called the elements. Further the elements classified into the three categories.
-Metal
-Non metal
-Metalloids
-Metal: Those substances which is capable for losing electron and make positive ion is called metal
 $ \text{M}\to {{\text{M}}^{+}}+{{\text{e}}^{-}} $
Some examples of metal are sodium, potassium, silver, zinc etc. In our periodic take there are 92 metals present.

Complete step by step solution
Noble metals: There are various metals which react with moisture to form the oxides called reactive metal.
Example if we left iron in the open environment or water the red brown layer of oxide forms on the surface of iron this is called rusting of iron. Sodium is the most reactive metal in the periodic table.
Respect that there are some which so no react with air or we can say that resistance to oxidation even at high temperature is called noble metal.
In this group rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum and gold of transition metal comes
Silver gold with copper, sometimes nickel also called coinage metal because they are used to prepare coins.
 Gold, silver, platinum, iridium, palladium are called precious metals because they are used in Jewellery making.

Note
There are several kinds of properties which are shown by metal as follows.
All metals are solid at room temperature except mercury.
Metal is lustrous in nature.
Metal possess high density
They are good conductor of heat and electricity
Metal shows ductility and malleability
Metals having generally high melting point and boiling point
Metal react with mineral and liberating $ {{\text{H}}_{2}} $ gas
Example $ \text{Zn}+{{\text{H}}_{2}}\text{ S}{{\text{O}}_{4}}\text{ }\to \text{Zn S}{{\text{O}}_{4}}+{{\text{H}}_{2}}\uparrow $
Mineral acids $ \to \text{HN}{{\text{O}}_{3}},\text{ }{{\text{H}}_{2}}\text{ S}{{\text{O}}_{4}},\text{ HCL} $ etc. which do not contains carbon atoms
They from basic oxides
Metal forms non-volatile hydrides if they combine with hydrogen
 $ 2\text{ Zn}+{{\text{H}}_{2}}\to \text{ 2 Zn H} $
The molecule of metal is monoatomic in vapour state.