Question

Based on the spectrum observed for incandescent white light, rank the colors in the visible spectrum from highest energy to lowest energy

Answer 1

See below.

Step-by-step explanation:

An incandescent lamp produces all colours of the visible spectrum, with wavelengths ranging from approximately 400 nm (violet) to 700 nm (red).

Since energy is inversely proportional to wavelength,

E ∝ 1/λ

a quantum of 400 nm violet light has more energy than one of 700 nm red light.

An incandescent lamp produces a relatively small amount of the high-energy blue/violet light ( see image below).

The table below gives the colours in the visible spectrum, ranked from highest to lowest energy.

Colour λ/nm

Violet 400 – 450

Blue 450 – 490

Cyan 490 – 520

Green 520 – 560

Yellow 560 – 590

Orange 590 – 635

Red 635 – 700