09. How We Use the EM Spectrum for Spectroscopy

1

• Electrons can only exist at given energy levels / orbitals and have fixed energy

2

• In normal conditions electrons fill up lowest energy levels first giving them stability

• This is called ground state

3

• When an atom is given energy (heating or electric field) atom becomes excited

• Electrons pushed up from low to high energy level

• Electron is promoted

4

• Higher energy states are unstable

• Electrons lose their excitation energy and fall back to ground states

• Energy lost is released as packet of energy called quantum energy or photon

5

• Frequency of light emitted depends on energy difference between energy levels

• Related to energy by E=hf