1. Electromagnetic Spectrum
Chemistry I

2. Ground vs. Excited State
Ground State – electrons are in positions of lowest energy possible (normal)
Excited State – electron is in a temporary position of higher energy than ground state
Very unstable; the electron quickly returns to the ground state
This releases energy, in the form of light

3. Emission of Energy
The amount of energy released when returning from excited state to ground state is different for each element
Some of the energy released has wavelengths within the visible light range

4. Nature of Light Light: electromagnetic energy (“radiation”)
Electromagnetic Spectrum: arrangement of wavelengths & frequencies for electromagnetic radiation
Wavelength (λ): distance between 2 points on adjacent waves
Measured in nm or m
Frequency (Ѵ): # of waves that pass through a point in time
Measured in Hertz (Hz) or s-1
Equation: C = λѴ
C = speed of light (3.00 x 108 m/s)
λ = wavelength in m
Ѵ = frequency in s-1