What Is the World Made Of?
In what ways do atoms emit and absorb light?
In the mid-1800s Robert Kirchhoff published three laws that describe how materials emit and absorb light:
- A hot solid or a hot, dense gas produces a continuous spectrum.
- A hot, low-density gas produces an emission-line spectrum.
- A continuous spectrum source viewed through a cool, low-density gas produces an absorption-line spectrum.