Why are metals lustrous?A. Light is transmitted through delocalized electronsB. They have a high boiling pointC. Light is reflected through delocalized electronsD. Light does not travel through metals at all.

The correct answer is C. Light is reflected through delocalized electrons.

Explanation:
Metals are lustrous (shiny) because of the behavior of their delocalized electrons. In metals, the outer electrons are not bound to any specific atom and can move freely within the metal lattice. These free-moving or delocalized electrons form what is known as an "electron sea."

When light hits the surface of a metal, the delocalized electrons can absorb the light energy and then re-emit it. This re-emission of light is what causes the shiny, lustrous appearance of metals. The electrons oscillate in response to the incident light, and this oscillation causes the light to be reflected back. This reflection of light from the surface of the metal gives it its characteristic shine.

Why Other Options Are Incorrect:
A. Light is transmitted through delocalized electrons: This is incorrect because metals are not transparent. They do not allow light to pass through; instead, they reflect it due to the presence of delocalized electrons.

B. They have a high boiling point: The boiling point of metals is unrelated to their lustrous property. A high boiling point is due to strong metallic bonds, not the interaction with light.

D. Light does not travel through metals at all: This is partially true, but it's not the reason for their luster. Light does interact with metals; it just doesn't pass through them. Instead, it is reflected, causing the luster.

Therefore, the correct answer, considering the nature of light interaction with metal surfaces, is that light is reflected through delocalized electrons (Option C).