Absorption and Emission Spectra

Practice Problems
Absorption and Emission Spectra

Directions:On this worksheet you will practice your knowledge of the properties of absorption and emission spectra as well as several historical experiments leading to their understanding.

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Question 1 An experiment is performed on a sample of atoms that have a ground state energy of -18 eV. While the gas was being illuminated with an incandescent light source instrumentation revealed that the sample only absorbed light at a 419 nm wavelength. To what energy level was the ground state sample initially excited?

-29.7 eV-15.0 eV-4.2 eV-4.7 eV

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Question 2 Later, when the illuminating light source was turned off, the sample radiated visible light of 588 nm. State an additional energy level required for the gas present in this sample.

-12.1 eV-17.1 eV-5.9 eV-2.1 eV

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Question 3 At which other wavelength, outside the visible range, must the gas emit radiation to permit it to return to its original ground state?

1458 nm1364 nm1438 nm1177 nm

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Question 4 The necessary condition(s) for an absorption spectra to be observed are:

an incandescent light source
a cool gas must be placed between the light source and the spectroscope
all of the lines present in the gas' emission spectra must be included in the wavelengths emitted by the light source

A, B, and Conly Conly A and Bonly Bonly A

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Question 5 A hypothetical atoms has 3 distinct energy states. Assuming all transitions are possible, how many emissions spectral lines can this atom produce?

213

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Question 6 The radiation curve for a 'white hot' incandescent solid peaks in the

infrared regionultraviolet regionred regiongreen regionblue region

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Question 7 Two lamps radiate the same amount of energy per second - that is, they have the same power rating. If one lamp emits a red beam and the other a violet beam, which beam contains the greatest number of photons?

the red beamthe violet beamboth contain the same number of photons

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Question 8 Which of the following was NOT an outcome of Rutherford's gold foil experiment?

some alpha particles bounced backwards since they collided with the hard nucleus of the gold atommost of the alpha particles passed through the gold foil undeflected since the atoms of gold are mostly composed of empty spacemost of the alpha particles travelled through the foil undeflected because the gold atoms had no net electrical chargesome of the alpha particles were deflected from their straight-line path by the positive charge of the nucleuseach of the other four statements is an acceptable outcome of Rutherford's experiment

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Question 9 Which of the following statement(s) is NOT true about Bohr's atomic model?

He declared that the hydrogen atom can exist, without radiating any energy, in several stable, stationary, states.
To establish orbitals at specified radii, he required that an electron’s angular momentum be quantized.
In his model, radiation would only be absorbed or released when an electron changed from one allowed orbitals to another.
He proved that the unique, discrete spectral lines, previously calculated by Balmer and Rydberg, were incorrect.

B and Donly Conly AA and Bonly Donly B