Question

What is meant by saying metals are lustrous?

Answer 1

Hint: Based on different properties a material is classified as metal or non-metal. These properties are classified as physical and chemical properties. Generally metals are lustrous, malleable and ductile. They are shiny in appearance.

Complete Answer:
As discussed earlier certain materials are classified as metals and non-metals based on what properties they possess. These include malleability, ductility, sonorous, lustrous, melting and boiling point, good conductor of electricity etc.
Lustre is the measurement of how well a material absorbs light. In simple terms it is the state of shining or gleaming by reflecting light. It depends on the material’s refractive power, degree of transparency and the structure. The quantity of reflected light produces different intensities of the same lustre.
Now that we are familiar with the lustrous properties, we must know why metals exhibit luster. This is because of the free movement of the electrons. These electrons move freely in an atom. Thus we can say that these free electrons tend to oscillate with a certain frequency. Due to this oscillation of free electrons the light transmitting or entering a metal is prevented. This results in reflecting back of incident light. The intensity of this incident light when reaches our eye, the metal appears to be lustrous.

Note:
A metal having lustrous does not mean they emit light or they are laminating the body. When a light falls on metals, they reflect the light, or in other words they capture the light, re-emit the photons at room temperature. Metals used in jewelry are good examples of metals possessing luster property.