Chapter 6 Flashcards
With respect to light production in stars, select all of the correct statements from the following list.
Hotter stars radiate more energy at higher frequencies.
Stars emit light mostly from their surfaces.
Black body radiators are generally cool.
Temperature is a measure of the heat produced by a star.
Hotter stars have a longer maximum intensity wavelength.
The temperature of a star can be roughly estimated from its color.
Heat flows from hot to cool regions.
Hotter stars radiate more energy at higher frequencies.
Stars emit light mostly from their surfaces.
The temperature of a star can be roughly estimated from its color.
Heat flows from hot to cool regions.
With respect to atoms, select all of the correct statements from the following list.
Electrons can be found anywhere outside a nucleus.
The number of neutrons determines the isotope of an atom.
Neutral atoms have the same number of protons as electrons.
The nucleus is completely composed of neutrons.
Electrons surround the nucleus.
Protons are positively charged.
Gaining or losing protons produces different ions.
The number of neutrons determines the isotope of an atom.
Neutral atoms have the same number of protons as electrons.
Electrons surround the nucleus.
Protons are positively charged.
Based on the interactions of light and matter, select all of the correct statements from the following list.
Bright-line spectra are created by emission.
Hot gases produce emission spectra.
The size of an electron’s orbit depends on its energy.
Absorption spectra have dark lines.
Hot solids emit continuous spectra.
Electrons will move to higher orbits when an atom absorbs enough energy.
Atoms absorb energy by emitting photons.
Bright-line spectra are created by emission.
Hot gases produce emission spectra.
The size of an electron’s orbit depends on its energy.
Absorption spectra have dark lines.
Hot solids emit continuous spectra.
Electrons will move to higher orbits when an atom absorbs enough energy.
With resepct to stellar spectra, select all of the correct statements from the following list.
Atoms can absorb or emit any amount of energy.
Every single star has a unique spectrum.
Balmer lines tend to be strong in all stellar spectra.
Stellar spectra are absorption spectra.
Spectra can reveal the chemical composition of stars.
Doppler shifts in spectral lines give clues to the motions of stars.
The Lyman and Paschen series of the hydrogen spectrum are not visible.
Stellar spectra are absorption spectra.
Spectra can reveal the chemical composition of stars.
Doppler shifts in spectral lines give clues to the motions of stars.
The Lyman and Paschen series of the hydrogen spectrum are not visible.
What kind of radiation do we (the human body) emit?
infrared
If you quadruple the temperature of a black body, by what factor will the total energy radiated per second per square meter increase?
256
Which of the following statements is true about the Celsius and Kelvin (absolute) temperature scales?
The size of one degree is the same on both scales.
The temperature of a gas is a measure of which of the following?
average motion of its atoms
When the sun is high above the horizon in a clear sky, it has a yellowish color. According to the black body radiation curves shown here, the sun’s surface temperature is most nearly which of the following?
6,000 K
If the temperature of star B is twice the temperature of star A, what can we say about the energy emitted by the surface of star B compared to the energy emitted by star A?
Each square meter emits sixteen times as much energy per second.
Which subatomic particle has a negative charge?
electron
The wavelength of maximum intensity that is emitted by a black body is which of the following?
inversely proportional to temperature
Of the following, which color represents the lowest surface temperature for a star?
red
The amount of electromagnetic energy radiated from every square meter of the surface of a black body each second is which of the following?
proportional to temperature to the fourth power
An atom that is ionized must have which of the following?
either more electrons than protons or more protons than electrons
Which of the following is true of an atomic nucleus?
All of these choices are correct.
A hot hydrogen gas emits which of the following?
only three spectral lines in the visible spectrum: red, blue, and violet
hat conditions produce a dark (absorption line) spectrum?
light from a continuous spectrum source passing through a cooler low-density gas
Which electron energy level transition corresponds to a hydrogen atom absorbing a visible light photon that has a wavelength of 656 nanometers?
he electron makes the transition from energy level 2 to energy level 3.
All stars are composed of mostly hydrogen and helium, yet many stars have no lines for hydrogen or helium in their spectra. What causes this apparent contradiction?
The surface temperature is such that the electrons are not at the proper energy levels to produce spectral lines at visible wavelengths.
You research the star Sirius and find that its spectral lines are blue-shifted. What does this tell you about Sirius?
It has a radial velocity that is toward us.
Suppose that you take the spectra of several stars and identify the 656 nm line of hydrogen. You then measure against the reference spectrum on the same image and find that some of the 656 nm lines are shifted due to the Doppler effect. Of the following shifted locations of this line, which one is that of a star that is moving away from us at the highest speed?
star E at 659 nm
