Question

Problem 1

: When an iron rod is heated to hundreds of degrees Celsius, it begins to glow red.

Why does it do this? (Hint: think about Feynman’s “jiggling” atoms, atomic structure, and the

nature of light)

(The answer need to be 4-5 sentences, and please write it clearly, thank you~)

Answer 1

For metals, when they are heated, the energy of the electrons increases. As the energy increases, the photons that are emitted fall in the wavelength of the visible spectrum. Initially, the metal is emitting infrared radiation invisible to the naked eye. When the emitted photons get more energy, they reach the red region of the visible spectrum. Persistent heating will take you to more colors in the spectrum i.e. Red --> Orange --> Yellow --> White.