Chapter 4
Hydrogen has absorption lines at 656 nm and 486 nm. Where are the emission lines from hydrogen in this part of the electromagnetic spectrum?
656 nm and 486 nm
For which of these scenarios is the wave model of light more convenient to use?
All of these choices are correct.
What are some of the things astronomers can learn about astronomical objects from their spectra?
All of these choices are correct.
What is the difference between emission and absorption in an atom?
In emission, the electron goes from a higher to a lower orbit.
Adam's toy gun emits blue light, Sue's emits red light, Bonnie's emits infrared light, and James' emits ultraviolet light. Which gun produces the most energetic light?
James
____ are found in the nucleus of atoms.
Protons
In the Orion constellation are stars Rigel, a blue supergiant, and Betelgeuse, a red supergiant. Which star has a greater surface temperature?
Rigel
Why is the absorption spectrum of atomic hydrogen different from that of helium?
The energy differences between orbitals in hydrogen are different from those in helium.
A star's emission line of 656 nm appears shifted to 649 nm in the spectrum. What can you conclude from this shift?
The star is approaching you with the speed of 3,200 km/s.
The maximum temperature on the Kelvin scale is called ______________.
There is no maximum temperature on the Kelvin scale.
Of the following objects, which will emit mostly infrared light?
a cup of hot coffee
In the wave model, light is ______________.
a mix of electric and magnetic energy
Compared to the entire electromagnetic spectrum, visible light is ____.
a small fraction of the possible wavelengths of light
Which one of the following is an example of a blackbody that you see in everyday life?
a stove burner
Zero Kelvin is also known as ____.
absolute zero
A(n) ___________ spectrum has dark lines on a continuous background.
absorption
What type of spectrum is observed when the light from a hot, dense body is seen through a cooler, tenuous gas?
absorption-line
Conservation of energy requires that if an atom absorbs a photon
an electron rises to a new orbital with an energy equal to that of the previous orbital plus the energy of the photon
Spectral lines shifted toward higher frequencies are called _____.
blue shifted
A candle emits what kind of spectrum?
continuous
An incandescent bulb emits what kind of spectrum?
continuous
What type of spectrum is emitted by a heated solid object (such as the filament of an incandescent bulb)?
continuous
As the wavelength of light increases, its energy ____.
decreases
A(n) ___________ spectrum has bright lines on dark background.
emission
If an electron moves from a higher energy orbital to a lower energy one, the atom will __________.
emit a photon
An X-ray telescope placed on the surface of the Earth can detect X-rays that are emitted from a distant astrophysical source.
false
In space, X-rays travel faster than radio waves.
false
The Doppler shift applies only to the line spectrum. It does not apply to the continuous (blackbody) spectrum.
false
The lower the frequency of the electromagnetic wave, the shorter its wavelength.
false
You are heating a jar full of hydrogen and observing its spectrum. If you add more hydrogen to the jar, the position of spectral lines will change.
false
The electromagnetic waves with the highest energy are ____.
gamma rays
The energy of an ultraviolet photon is ____ a photon in the visible part of the spectrum.
higher than
As the frequency of light increases, its energy ____.
increases
The energy of a radio photon is ____ a photon in the visible part of the spectrum
lower than
A photon of blue light has ______________ a photon of red light.
more energy than
Is light a wave or a particle?
neither a wave nor a particle
Uncharged particles in an atom are called ____.
neutrons
A ____ is a particle of light.
photon
Positively-charged particles in an atom are called ____.
protons
Which kind of electromagnetic radiation has a wavelength that is about the size of a person?
radio
List these electromagnetic radiations from lowest to highest energy.
radio waves, infrared, visible light, ultraviolet, X-rays, gamma rays
Which of the following colors travels most quickly through glass or plastic?
red
The spectral lines of a star will appear ____________________ if the star is moving away from the Earth.
red shifted (i.e., shifted toward the longer wavelengths)
As a solid is heated (from a low to a high temperature) the radiated light will move through what sequence of colors?
red, yellow, blue
In materials like glass or water the speed of light is _________.
reduced
Determining the composition of an astronomical body using its emitted or reflected light is called ____.
spectroscopy
Star A is blue, Star B is yellow, and Star C is red. Which one of these is the hottest star?
star A
If an atom emits a photon, that photon must have a wavelength __________.
that corresponds to the energy difference between two orbitals
A significant source of gamma rays is __________________.
the collision of two black holes
The visible spectrum is ___________________.
the range of wavelengths of light that human eyes can detect
A continuous blackbody spectrum provides information about the surface temperature of the object.
true
A temperature of 0 Kelvin means there is essentially no motion at the atomic level.
true
An atom with 6 protons and 6 neutrons is a carbon atom, and an atom with 6 protons and 7 neutrons is also a carbon atom.
true
The Doppler shift is the same if the emitting object is moving towards you at some speed, or you (the observer) are moving towards it at that speed and it is still.
true
The chemical composition of a gas can be determined by analysis of the spectral lines of the gas.
true
When an atom emits light, an electron in it moves from a higher to a lower energy level.
true
A night vision camera
uses a detector sensitive to infrared light, so you can see objects that are warmer than their surroundings.
Which of the following colors has the shortest wavelength?
violet
The mixing of light of all visible colors results in ____ light.
white
Visible light coming from the Sun is a combination of all colors called ____ light.
white