Absorption and emission spectroscopy are both techniques used to study atoms and molecules, but they work in opposite ways:
Absorption Spectroscopy:
- Measures how much light a substance absorbs.
- A light source shines through the sample, and atoms absorb specific wavelengths.
- The amount of light absorbed tells us the concentration of the element in the sample.
- Example: Atomic Absorption Spectroscopy (AAS).
Emission Spectroscopy:
- Measures the light emitted by atoms or molecules.
- The sample is heated or energized, causing atoms to emit light at specific wavelengths.
- The intensity of the emitted light tells us the amount of the element present.
- Example: Flame Emission Spectroscopy.
Key difference:
- Absorption looks at light absorbed by atoms.
- Emission looks at light given off by atoms.
In short, absorption detects what is taken in, while emission detects what is released.