c = λf
E= hf
c = 3.00 x 108 m
s
h = 6.6262 x 10
-34
J •s
Hz = 1
s
1. A certain photon of light has a wavelength of 422 nm. What is the frequency of the
light?
λ = 422 nm (which is 0.000000422 m)
f=?
c = λf
c=f
λ
(3.00 x 108m)
= 7.11 x 1014 Hz
(s)(0.000000422m)
2. What is the energy of the photon from question 1?
-34
E= hf
E = (6.6262 x 10
f = 7.11 x 1014 Hz or
7.11 x 1014
J • s)( 7.11 x 1014 )
s
E = 4.71 x 10-19 J
s
3. What is the energy of a quantum of light with a frequency of 7.39 X 10 14 Hz?
-34
E = (7.39 x 1014) (6.6262 x 10
E = hf
J • s)
(s)
f = 7.39 X 1014 Hz or
E = 4.90 x 10-19 J
7.39 x 1014
S
4. A certain blue light has a frequency of 6.91 X 1014 Hz. What is the wavelength of the
light?
c = λf rearranged to:
f = 6.91 X 1014 Hz or
(3.00 x 108m)(s) = λ
(s)(6.91 x 1014)
c=λ
f
f = 6.91 X 1014
s
λ = 0.000000434m or
434 nm
5. The energy of a quantum of light is 2.84 X 10-19J. What is the frequency of the light?
E = hf
E= 2.84 X 10-19J
rearranged to:
(2.84 X 10-19J)
=f
(6.6262 x 10.34 J• s)
E=f
f = 4.29 x 1014
H
s
or
4.29 x 1014 Hz
6. Write the alpha decay equation for the following elements:
U→
238
4
92
2
He +
Cm → 4 He + 243Pu
234
247
90
96
Th
2
94
7. Write the beta decay equation for the following elements:
U→
238
238
92
93
0
Np +
Cm →
e
-1
247
247
Bk + 0 e
96
97
-1
8. Write the gamma decay equation for the following elements:
U* →
U+ 0ᵞ
238
238
92
92
0
Cm* →
Cm + 0 ᵞ
247
247
96
96
0
9. What is the difference between fission and fusion?
Fission splits a large, heavy nucleus (like Uranium) into two smaller, lighter nuclei.
Fusion combines two small, light nuclei (like hydrogen), into a larger, more stable
nucleus (like helium).
10. What are the three types of radiation/decay? Describe what happens to cause each
type.
Alpha radiation: Caused when the nucleus contains too many protons and the
nuclear forces that hold them together “break”. A helium atom is expelled during the
decay process.
Beta radiation: Caused when the number of neutrons is too high compared to the
number of protons. The atom converts a neutron into a proton and an electron. The
proton stays in the atom, but the electron is expelled.
Gamma radiation: Caused when an atom has too much energy and has become
unstable. As it lowers back into a stable state of energy, photons of energy known
as gamma rays are emitted. These are not particles that have mass, they are pure
energy.
11. Be able to define wavelength, amplitude, frequency, crest, trough, origin (of a wave).
Be able to pick out the correct diagrams if given multiple choice.
Wavelength = the length of one complete wave
Amplitude = the distance from the origin to the top of a crest or bottom of a trough
Frequency = the number of waves that pass a certain point in a given amount of
time. It is measure in Hz (hertz), or 1/s.
Crest = a peak of a wave
Trough = a valley of a wave
Origin = the center line drawn directly through the middle of the wave.
12. Describe Planck and Einstein’s contributions to wave and particle science.
Planck developed the quantum theory and planck’s constant.
Einstein developed the Wave-Particle Duality theory, discovered the
photoelectric effect, and developed the formula for deriving energy from the
change in mass and speed of light (e = mc2).
13. What is a photon?
A photon is a particle of light that carries a quantum of energy.
14. Be able to explain why the energy release from a nuclear change is so great. *hint:
E = mc2 slide.
Because the value for c2 is so large, even a tiny amount of mass defect multiplied
by such a large number would result in an enormous energy release.
15. Be able to label a diagram of a nuclear powerplant.
16. Order the following in terms of lowest to greatest energy release: fission, coal fired
power, fusion.
Coal fired power, fission, fusion
17. Be able to determine the color of a given wavelength of light (memorize the
wavelengths of the main light colors).
18.
Be able to list the following waves in order of energy:
Gamma rays, x rays, UV waves, Visible light waves, Infrared waves, microwave
waves, radio waves This order was highest to lowest energy
19. Know how wavelength, frequency, and energy relate to each other:
Wavelength and frequency are inversely proportional. Energy and frequency are
directly proportional.