Exam 5: The Nature of Light

An electron is in the n = 3 energy level in a hydrogen atom. To ionize this atom it is necessary for the electron to gain a minimum of how much energy?

The wavelengths λ of the emission lines from hot hydrogen gas depend on an integer n according to:

Light of a single wavelength falls on a screen with two narrow, closely spaced slits. On a second screen, a short distance beyond the first:

If light from a hot, dense star is viewed through a cool cloud of gas (See Figure 5-17 of Universe, 11th ed.): ​ ​

The typical size of an atom is:

One atom of ¹³C has how many particles?

The temperature of a gas cloud in space is directly related to and representative of the:

A photon is:

The energy of a photon of x rays, compared to the energy of a photon of visible light, is:

An astronomer photographs the spectrum of an object and finds a spectral line at 499 nm wavelength. In the laboratory, this spectral line occurs at 500 nm. According to the Doppler effect, this object is moving:

The energy flux arriving at Earth from the Sun is known as the solar constant and has a value of 1.37 × 10³ watts per square meter. Assuming that the atmosphere absorbs 50% of the energy and that a 5-m² roof collector is available to collect energy with a 30% efficiency, how much of this solar energy would then be available for use in the house for water or house heating, etc.? (1 KW = 1 kilowatt = 1000 W)

What is the energy in eV of a photon with the wavelength of Lyman Lα at 121.5 nm in the ultraviolet range?

The specific sequence of spectral line series emitted by excited hydrogen atoms, in order of increasing wavelength range, is:

The Balmer series of hydrogen has a series limit (at 364.6 nm) because hydrogen in the n = 2 state:

As a new star evolves from cool dust and gas to a hot star, the peak wavelength of its spectrum of electromagnetic radiation:

The mass of a proton is:

A piece of iron is heated from 400 K to 800 K (127°C to 527°C). By what factor will the total energy per second emitted by this iron increase?

In comparing photons of different wavelengths, we find that the energy carried by a photon:

The rear brake lights on a car emit white light but are covered with plastic that allows only pure red light to pass through. What color of plastic would the red light have to pass through in order to emerge as green light?

The wavelength of the peak in the Sun's output spectrum is about 500 nm. If the Sun's surface temperature doubled, what would this peak wavelength become?