Question

The property of metal having shining surface is called :
A. Luster
B. Sonority
C. Conductivity
D. All of the above

Answer 1

Hint: The elements which have the capability to donate the electrons are called metals. The metals have loosely bounded free valence electrons in their orbitals and to get stability metals donates their nonbonded electrons.

Complete answer:
- In the question it is asked the reason behind the shiny surface of the metal.
- The freely bound electrons on the metal surface absorb energy freely and are excited to higher energy levels.
- After reaching higher energy levels the electrons liberate the absorbed energy and reach the ground state.
- At the time of reaching ground state form excited state electrons are going to lose the energy in the form of light.
- The emitted energy makes the surface of the metal look shiny.
- The property of metal to get a shiny surface due to the reaching of electrons to ground state is called luster.
- Therefore all metals in their pure state contain a luster surface.
- Therefore the property of metal having a shining surface is called luster.

So, the correct option is A.

Note:
The metals like gold (Au), copper (Cu) and silver (Ag) have a metallic surface due to the free bounded electrons in their valence orbitals. Due to this luster property metals are very costly in nature and in pure form only they will show the luster property.