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## Light and Atoms

1. What is the speed of light expressed in units of miles per hour?
2. The average distance between Mars and Earth is about 1.3 × 108 miles. How long does it take data from the Spirit rover to be transmitted from the surface of Mars to receivers on Earth? (Hint: radio waves are a kind of light.)
3. The wavelength of the green light from a traffic signal is centered at 522 nm (1 × 109 nm = 1 m). What is the frequency of this radiation?
4. The blue color of the sky results from the scattering of sunlight by air molecules. The blue light has a frequency of about 7.5 × 1014 Hz. What is the wavelength, in nm, associated with this radiation? Also, calculate the energy of a single photon of this radiation.
5. A photon has a frequency of 657 MHz. What is the wavelength of this light in cm? What part of the spectrum is this photon a part of? What is the energy in J of this photon?
6. The transition of an electron from the 7th shell of a hydrogen atom to the 4th shell results in the emission of a photon with an energy of 9.18 × 10-20 J. What is the wavelength of this radiation? What region of the spectrum does it belong to?
7. The absorption of a photon with an energy of 4.84 × 10-19 J by an electron in the 2nd shell of a hydrogen atom results in its transition to the 6th shell. What is the wavelength of this radiation? What region of the spectrum does it belong to?

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1. Two energy levels in an atom are at -5.7 eV and -7.2 eV.
1. How much energy in electron-volts (eV) must a photon have to make an electron move from the lower level to the upper level?
2. What is the energy in joules (J) of a photon emitted when an electron moves from the upper level to the lower level?
3. Draw an energy-level diagram showing the transition of an electron between these two levels that results in the emission of a photon.
4. What is the frequency in hertz (Hz or 1/s) of light that is emitted when an electron moves from the upper level to the lower level?
5. What is the wavelength in meters (m) of light that is emitted? What part of the spectrum does this light belong to?
This page is the final in the series starting with the Light and the Electro-magnetic Spectrum Group Acitivity
Next in the series for this activity: Light and Graphing the Relationship between Wavelength and Frequency and Graphing the Relationship between Energy and Frequency
Here is the homework assignment that goes with this
group activity. Give this after the group activity has been completed.
Last updated: Jan 25, 2016       Home