Exam 5: Light

Saying that something is quantized means that it:

Figure 1 -The difference in energy between the n = 2 and n = 1 electronic energy levels in the hydrogen atom is 1.6 * 10^-18 J. If an electron moves from the n = 1 level to the n = 2 level, will a photon be emitted or absorbed? What will its energy be, and what type of electromagnetic radiation is it? Use the electromagnetic spectrum shown above to answer this question.

Which formula denotes how the speed of light is related to its wavelength and frequency?

What two factors control a planet's surface temperature if it has no atmosphere?

The average red giant in the night sky is about 1,000 times more luminous than the average main-sequence star. If both kinds of stars have about the same brightness, how much farther away are the red giants compared to the main-sequence stars?

Why is an iron atom a different element than a carbon atom?

What does it mean to say that an object is in thermal equilibrium?

The Doppler shift can be used to determine the _________ of an object.

If you observe a star, you will see:

Star A and star B appear equally bright in the sky. Star A is twice as far away from Earth as star B. How do the luminosities of stars A and B compare?

Compare and contrast the wavelengths, frequencies, speeds, and energies of red and blue photons.

Use the figure below to answer the following question: Which of these statements about the amplitude and wavelength of the two waves shown is correct?

Why do we see black lines in an absorption spectrum if the absorbed photons are (almost) instantaneously reemitted by the atoms in the cloud?

A radio photon travels slower than a gamma ray photon.

Imagine a satellite is orbiting a planet as shown in the image below. This satellite gives off radio waves with a constant wavelength of 1 meter. An observer on Earth then measures the signal from the satellite when it is at the locations labeled A-D. For each of these locations, how does the wavelength received compare to the wavelength that the satellite gave off?

If the frequency of a beam of light were to increase, its period would _________ and its wavelength would _________?

As wavelength increases, the energy of a photon _________ and its frequency _________.

When an electron moves from a higher energy level in an atom to a lower energy level:

A spaceship approaches Earth at 0.9 times the speed of light and shines a powerful searchlight onto Earth. How fast will the photons from this searchlight be moving when they hit Earth?

The emission spectrum of a helium atom is identical to that of a carbon atom.