Early models to Quantum Model Atomic Structure Early models to Quantum Model

Dalton’s Model Thomson’s Model Rutherford’s Model Bohr’s Model

If an electron absorbs the energy of colliding particles of matter or photons of electromagnetic radiation, the electron will be raised to a higher energy level causing the atom to be in an excited state.

The photons energy is absorbed by an electron in an atom only if the photon’s energy corresponds exactly to an energy level difference possible for the electron.

Each element has different energy level differences Each element has different energy level differences. This is why each element will produce a unique emission (bright-line) spectrum when the excited electrons return to the ground state and emit the energy they acquired as a photon of light with a specific frequency and color.

An energy level diagram indicates the energy levels and the possible energy level transitions for the electrons in an atom of a particular element. There are energy level diagrams for hydrogen and mercury in your Reference Tables. Note the energy values are in units of electron volts (eV).

The energy required to remove an electron from an atom to form an ion is called ionization potential. The energy levels are quantized and the horizontal lines indicate the distances from the zero energy level, which is the energy level of an electron that has been completely removed (n = ).

Patterns in Nature: Aurorae The energy levels have negative values. When an electron moves closer to the nucleus, the total energy becomes less negative. Patterns in Nature: Aurorae National Geographic

Ephoton = Ei - Ef Ephoton = energy of photon Ei = initial energy of electron in its excited state Ef = final energy of electron in the lower energy level

Ephoton = Ei - Ef Do practice problems p757 #1-3

Ephoton = Ei - Ef Do practice problems p757 #1-3 1) n=2 -3.40 ev 2) 1.89 ev = 3.02 x 10-19 J 3) 2.55 ev = 4.08 x 10-19 J