Chapter 5 Concept Review

Suppose you had molecular oxygen (O2) chilled enough so that it was in liquid form. Which of the following best describes the phase changes that would occur as you heated the liquid oxygen to high temperature?

It would evaporate into a gas, then the molecules would dissociate into individual oxygen atoms, then the atoms would become increasingly ionized as you continued to raise the temperature.

Consider an atom of oxygen in which the nucleus contains 8 protons and 8 neutrons. If it is doubly ionized, what is the charge of the oxygen ion and how many electrons remain in the ion? A) Charge = +2, number of remaining electrons is 6 B) Charge = +2, number of remaining electrons is 8 C) Charge = +2, number of remaining electrons = 2 D) Charge = -2, number of remaining electrons= 10

A) Charge = +2, number of remaining electrons is 6

Which of the following statements about thermal radiation is always true? A) a hot object emits more radiation per unit surface area than a cool object B) all the light emitted by hot object has higher energy than the light emitted by a cooler object C) a hot object produces more total infrared emission than a cooler object D) a cold object produces more total infrared and radio emission per unit surface area than a hot object

A) a hot object emits more radiation per unit surface area than a cool object

Which of the following statements is true of green grass? A) it absorbs red light and reflects green light B) it absorbs red light and emits green light C) it transmits all colors of light except green D) it means the lawn is healthy

A) it absorbs red light and reflects green light

Which of the following best describes why we say that light is an electromagnetic wave? A) the passage of a light wave can cause electrically charged particles to move up and down B) the term electromagnetic wave arose for historical reasons C) light can be produced by electric and magnetic appliances D) light is produced only when massive fields of electric and magnetic energy collide with one another

A) the passage of a light wave can cause electrically charged particles to move up and down

Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude? A) the star is moving toward us B) the star is getting hotter C) the star is getting colder D) the star is moving away from us

A) the star is moving toward us

Each of the following describes an Atom 1 and an Atom 2. In which case are the two atoms different isotopes of the same element? Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons

Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons

Suppose you have a 100 watt light bulb that you leave turned on for one minute. How much energy does it use? A) 6,000 watts B) 6,000 joules C) 100 joules D) 100 Watts

B) 6000 joules (because it's j per second)

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet? A) the planet is in the process of falling apart B) the planet is rotating C) the planet is in the process of formation D) we must actually be observing moons orbiting the planet in opposite directions not the planet itself

B) the planet is rotating

Suppose you are listening to a radio station that broadcasts at a frequency of 97 mhz. Which of the following statements is true? A) the radio station broadcasts its signal with a power of 97 million watts B) the radio waves from the radio station are causing electrons in your radio's antenna to move up and down 97 million times each second C) the radio waves received by your radio are not light waves like those we talk about in astronomy, but rather are a special type of sound wave D) the radio waves from teh radio station have a wavelength of 97 million meters

B) the radio waves from the radio station are causing electrons in your radio's antenna to move up and down 97 million times each second

All of the following statements about the sun's corona are true. Which one explains why it is a source of X rays? A) the corona lies above the visible surface of the sun B) the temperature of the corona's gas is some 1-2 mill Kelvin C) the corona's gas consists mostly of hydrogen and helium D) the corona's structure is largely shaped by magnetic field

B) the temperature of the corona's gas is some 1-2 mill Kelvin

Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true? A) we can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals B) the total amount of light in the spectrum tells us the star's radius C) the peak of the star's thermal emission tells us its temp: hotter stars peak at shorter bluer waves D) shifts in the wavelengths of spectral lines compared to the wavelengths of those same lines measured in a lab on earth can tell us the star's speed toward or away from us

B) the total amount of light in the spectrum tells us the star's radius

The planet Neptune is blue in color. How would you expect the spectrum of visible light from Neptune to be different from the visible-light spectrum of the Sun? A) Neptune's spectrum would peak at a much longer wavelength than the Sun's spectrum B) the two spectra would have similar shapes, except Neptune's spectrum would be missing a big chunk of the red light that is present in the Sun's spectrum C) the two spectra would have similar shapes, except Neptune's spectrum would be missing a big chunk of the blue light that is present in the sun's spectrum D) there is no way to predict the answer since planets and stars are made of such diff things

B) the two spectra would have similar shapes, except Neptune's spectrum would be missing a big chunk of the red light that is present in the Sun's spectrum

Suppose a photon has a frequency of 300 million hertz (300 megahertz). What is its wavelength? A) 300 million meters B) 1/300,000 meter C) 1 meter D) a photon's wavelength cannot be determined from its frequency

C) 1 Meter

Gamma rays have a very small... A) mass B) frequency C) wavelength D) energy

C) Wavelength

Which of the following statements about X rays and radio waves is not true? A) X rays have higher frequency than radio waves B) x rays and radio waves are both forms of light, or electromagnetic radiation C) X rays travel through space faster than radio waves D) X rays have shorter wavelengths than radio waves

C) X rays travel through space faster than radio waves

No object produces a perfect thermal radiation spectrum, but many objects produce close approximations. Which of the following would not produce a close approximation to a thermal radiation spectrum? A) a filament in a standard light bulb B) you C) a hot, thin low density gas D) a star

C) a hot, thin low density gas

Suppose that Star X and Star Y both have redshifts, but Star X has a larger redshift than Star Y. What can you conclude? A) Star x is hotter than star y B) star y is moving away from us faster than star x C) star x is moving away from us faster than star y D) star x is moving away from us and star y is moving toward us

C) star x is moving away from us faster than star y

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? A) the cloud is extremely hot B) the cloud is visible primarily because it reflects light from nearby stars C) the cloud is cool and lies between you and a hot star D) the cloud is cool and very dense

C) the cloud is cool and lies between you and a hot star

Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All the following statements about Betelgeuse are true. Which one can you infer from its red color? A) it is much brighter than the sun B) it is moving away from us C) is it much more massive than the Sun D) its surface is cooler than the surface of the sun

D) its surface is cooler than the surface of the sun

Suppose that two stars are identical in every way - for example, same distance, same mass, same temperature, same chemical composition, and same speed relative to Earth - except that one star rotates faster than the other. Spectroscopically, how could you tell the stars apart? A) there is no way to tell the stars apart spectroscopically B) the faster rotating star will have an emission line spectrum while the slower rotating will have an absorption C) the peak of thermal emission will be at a shorter wavelength for the faster rotating star than for the slower rotating star D) the faster rotating star has wider spectral lines than the slower rotating star

D) the faster rotating star has wider spectral lines than the slower rotating star

Which of the following statements about electrons is not true? A) within an atom, an electron can have only particular energies B) electrons can jump between energy levels in an atom if they receive or give up an amount of energy equal to the difference in energy between the energy levels C) an electron has a negative electrical charge D) electrons have very little mass compared to protons or neutrons E) electrons orbit the nucleus rather like planets orbiting the sun

E) electrons orbit the nucleus rather like planets orbiting the sun