When light interacts with a material by being transmitted through or reflected off it, what happens to the energy of the light?

• A. The energy of the light increases as it passes through or reflects off the material.
• B. The energy of the light is always absorbed completely by the material.
• C. The energy of the light remains unchanged during transmission or reflection.
• D. The energy of the light is converted entirely into heat.

Answer: (C)

Verified step by step guidance

1. Understand that when light interacts with a material, it can be transmitted, reflected, or absorbed. Each of these processes affects the energy of the light differently.
2. Recall the principle of conservation of energy, which states that energy cannot be created or destroyed, only transformed or transferred.
3. In the case of transmission or reflection, the light's energy is not absorbed by the material but rather continues to exist either by passing through (transmission) or bouncing off (reflection).
4. Therefore, the energy of the light remains essentially unchanged during transmission or reflection, although its direction or speed may change depending on the material's properties.
5. Only when light is absorbed by the material is its energy converted into other forms, such as heat, but this does not happen during pure transmission or reflection.