Transcript II. Bohr Model of the Atom

II. Bohr Model of the Atom
(p. 125-128)
CH. 5 - ELECTRONS IN ATOMS
C. JOHANNESSON
A. Line-Emission Spectrum
excited state
ENERGY IN
PHOTON OUT
ground state
C. JOHANNESSON
B. Bohr Model
e- exist only in orbits with specific amounts of
energy called energy levels
Therefore…
◦ e- can only gain or lose certain amounts of energy
◦ only certain photons are produced
C. JOHANNESSON
C. JOHANNESSON
B. Bohr Model
65
4
Energy of photon depends on the
difference in energy levels
3
Bohr’s calculated energies matched
the IR, visible, and UV lines for the H
atom
2
1
C. JOHANNESSON
C. Other Elements
Each element has a unique bright-line emission
spectrum.
◦ “Atomic Fingerprint”
Helium
Bohr’s calculations only worked for
hydrogen! 
C. JOHANNESSON
D. Bohr Practice
Use the Bohr Model/EM Spectrum on p. 8 of your
reference tables.
1. What type of light is produced when an
electron moves from n=4 to n=1?
2. What wavelength is produced when an
electron moves from n=3 to n=2?
3. What color of light is number 2?
4. Which has more energy: red light or violet
light?
5. Which has less energy: Radio waves or
ultraviolet radiation?
6. Which has a smaller wavelength green or
infrared?
C. JOHANNESSON