Honor Chemistry Name: __________________________________
Chapter 11: Electromagnetic Energy Date _____/_____/______ Period _____
1. Write the correct answer in the space to the left.
a. High Electromagnetic energy with a short wavelength has a (high / low) frequency.
b. High Electromagnetic energy with a short wavelength has a (high / low) energy.
c. Photon Term for a packet of electromagnetic radiation.
d. Released (Emitted) Energy is (absorbed / released) when an electron moves from the excited to
ground state.
e. Shorter Blue light has a (longer / shorter) wavelength than red.
f. Less Red light has (less / more) energy than green light.
g. False Radio waves can be heard by the human ear. (True / False)
h. Frequencies Atoms only emit certain ________________ of light.
i. Wavelength Term for distance between two consecutive peaks in a wave.
j. Visible Light Portion of electromagnetic radiation with wavelength approximately
400 - 700 nm.
k. Ground State Lowest possible energy state of an atom.
l. Orbits According to Bohr, the electron in the H atom moves around the nucleus in
circular paths called _________________ .
m. Orbital Modern atomic theory describes the region in space with high probability of
finding an electron a(n) __________________.
n. Quantum The term ______________ means that only certain values of energy can
be lost or gained by an atom.
o. 3.00 x 108 m/sec In the equation; E=mc2, c= ? What is the numerical value?
2. What is the frequency of a photon of energy that has a wavelength of 620 nm? Use Fig. 11.4 to
determine its color.
c = ln = n = c = 3.00 x 108 m/sec = 4.8 x 1014 Hz
l 6.2 x 10-7m
3. Gamma radiation has a frequency of 3 x 1020 Hz while ultraviolet radiation has a frequency of
8 x1014 Hz. Compare the wavelengths of a photon of gamma radiation with ultraviolet radiation.
c = ln = l = c = 3.00 x 108 m/sec = 1 x 10-12 m
n 3 x 1020 Hz
c = ln = l = c = 3.00 x 108 m/sec = 4 x 10-7 m
n 8 x 1014 Hz
Gamma radiation has a higher frequency than ultraviolet radiation. Having a higher frequency means that gamma rays have a much shorter wavelength and carry more energy.
4. Use Fig. 11.4 to determine the frequency of heat radiation. What is heat radiation also know as?
c = ln = n = c = 3.00 x 108 m/sec = 3 x 1012 Hz
l 1 x 10-4 m
Heat radiation is also known as infrared radiation.
5. Calculate the energy of a photon of energy that has a frequency of 2.5 x 1016 Hz.
E = hn = (6.626 x 10-34 J ● sec)(2.5 x 1016 Hz) = 1.7 x 10-17 J
6. A photon of blue-green light has an energy of 4.4 x 10-19 J. What is the wavelength of this light?
E = hn = n = E = 4.4 x 10-19 J = 6.6 x 1014 Hz
h 6.626 x 10-34 J ● sec
c = ln = l = c = 3.00 x 108 m/sec = 4.5 x 10-7 m
n 6.6 x 1014 Hz
7. Determine the energy of an X-ray that has a wavelength of 1 x 10-10 m.
c = ln = n = c = 3.00 x 108 m/sec = 3 x 1018 Hz
l 1 x 10-10 m
E = hn = (6.626 x 10-34 J ● sec)(3 x 1018 Hz) = 2 x 10-15 J
8. (Mini-Essay) Describe the events that occur in an atom when energy is applied to it. What accounts
for the phenomena of the emission of discrete wavelengths of light by excited atoms?
When an atom absorbs energy (usually in the form of heat or electrical energy), the valence electrons use the absorbed energy to jump from a lower energy level (ground state) to a higher energy level (excited state). When the excited electron falls back to the ground state, most of the energy is emitted in the form of light energy. The light energy that is released is the energy that was needed for the valence electrons to jump to the excited states (discrete wavelengths).
Honors Chemistry Name ____________________________
Chapter 11: Electromagnetic Radiation Worksheet Date _____/_____/_____ Period _____
Perform the following calculations and answer the following questions involving energy, wavelength, and frequency for the various forms of electromagnetic radiation.
1. Calculate the frequency of that light and identify the color of light has a wavelength of
565 nm? c = ln = 3.00 x 108 m/sec = (5.65 x 10-7 m)(n)
n = 5.31 x 1014 Hz
Color = Green/Yellow
2. Calculate the wavelength in nm of a photon with energy of 2.71 x 10-19 J and identify the
type of electromagnetic radiation.
E = hn = 2.71 x 10-19 J = (6.626 x 10-34 J ▪ sec) n
n = 4.09 x 1014 Hz
c = ln = 3.00 x 108 m/sec = l (4.09 x 1014 Hz)
l = 7.33 x 10-7 m = 733 nm
Radiation = Infrared Radiation
3. Calculate the wavelength used to transmit the radio signal for WISH 99.7 MHz.
c = ln = 3.00 x 108 m/sec = l (9.97 x 107 Hz)
l = 3.01 m
4. Compare the red part of the visible spectrum to the violet part of the visible spectrum by
applying frequency, wavelength, and energy.
The red part of the visible spectrum has a lower frequency, lower energy and longer wavelength than the violet end of the visible spectrum.
5. Calculate the frequency and energy for a particular wave of electromagnetic radiation that
has a wavelength of 0.010 m and identify the type of electromagnetic radiation.
c = ln = 3.00 x 108 m/sec (0.010 m)n
n = 3.0 x 1010 Hz
E = hn = (6.626 x 10-34 J ▪ sec) (3.0 x 1010 Hz )
E = 2.0 x 10-23 J
Radiation = Microwaves (1.0 x 100 cm)
6. The energy of a photon of EM radiation is 2.09 x 10-18 J. Calculate the wavelength of the
photon.
E = hn = 2.09 x 10-18 J = (6.626 x 10-34 J ▪ sec) n
n = 3.15 x 1015 Hz
c = ln = 3.00 x 108 m/sec = l(3.15 x 1015 Hz)
l = 9.52 x 10-8 m
7. Calculate the wavelength and energy for a particular wave that has a frequency of
5.0 x 10 17 Hz and identify the type of electromagnetic radiation.
c = ln = 3.00 x 108 m/sec = l(5.0 x 10 17 Hz)
l = 6.0 x 10-10 m
E = hn = (6.626 x 10-34 J ▪ sec) (5.0 x 10 17 Hz)
E = 3.3 x 10-16 J
Radiation = X-Rays
8. What is the frequency of a wave that has a wavelength of 7.6 x 10 7 nm? What type of
electromagnetic radiation is it?
c = ln = 3.00 x 108 m/sec = (0.076 m)n
n = 3.9 x 109 Hz
Radiation = Microwaves
9. What is the color of the visible light that has a wavelength of 5.0 x 10 -7 m?
Color = Green