Chapter 5

Question 1

Ions

Answer 1

atoms with a positive or negative electrical charge

Question 2

Atomic number

Answer 2

the number of protons in an atom

Question 3

Wavelength

Answer 3

the distance between adjacent peaks of a wave

Question 4

Protons

Answer 4

Particles with positive electrical charge found in atomic nuclei, built from three quarks

Question 5

Thermal radiation

Answer 5

the spectrum of radiation produced by an opaque object that depends only on the object’s temperature

Question 6

Visible light

Answer 6

the light our eyes can see, ranging in wavelength from about 400 to 700 nm

Question 7

Angular resolution

Answer 7

the smallest angular separation that two pointlike objects can have and still be seen as distinct points of light

Question 8

Redshift

Answer 8

a Doppler shift in which spectral features are shifted to longer wavelengths, observed when an object is moving away from the observer

Question 9

Intensity

Answer 9

a measure of the amount of energy coming from light of specific wavelength in the spectrum of an object

Question 10

Transmission

Answer 10

(of light) the process in which light passes through matter without being absorbed

Question 11

Light-collecting area

Answer 11

the area of the primary mirror or lens that collects light in a telescope

Question 12

Frequency

Answer 12

the rate at which peaks of a wave pass by a point, measured in units of 1/s

Question 13

Continuous spectrum

Answer 13

a spectrum (of light) that spans a broad range of wavelengths without interruption by emission or absorption lines

Question 14

Electrons

Answer 14

fundamental particles with negative electric change

Question 15

Ultraviolet

Answer 15

light with wavelengths that fall in the portion of the electromagnetic spectrum between visible light and x-rays

Question 16

Thermal radiation spectrum

Answer 16

an object that produces a thermal radiation spectrum

Question 17

Electromagnetic spectrum

Answer 17

the complete spectrum of light, including radio waves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays

Question 18

Doppler effect

Answer 18

the effect that shifts the wavelengths of spectral features in objects that are moving toward or away from the observer

Question 19

Elements

Answer 19

a substance made from individual atoms of a particular atomic number

Question 20

Speed of light

Answer 20

the speed at which light travels, which is about 300,000 km/s

Question 21

Adaptive optics

Answer 21

a technique in which telescope mirrors flex rapidly to compensate for the bending of starlight caused by atmospheric turbulence

Question 22

Reflecting telescope

Answer 22

a telescope that uses mirrors to focus light

Question 23

emission lines

Answer 23

a bright band of single color, superimposed on a fainter or completely absent rainbow of light, occurring when light viewed through a diffraction element such as a prism shows an excess of photons at or near a specific wavelength

Question 24

energy levels

Answer 24

broadly speaking, what can make matter move

Question 25

Gamma rays

Answer 25

light with very short wavelengths- shorter than those of x-rays

Question 26

Isotopes

Answer 26

forms of an element that have the same number of protons but different numbers of neutrons

Question 27

X-rays

Answer 27

light with wavelengths that fall in the portion of the electromagnetic spectrum between ultraviolet light and gamma rays

Question 28

Infrared

Answer 28

light with wavelengths that fall in the portion of the electromagnetic spectrum between radio waves and visible light

Question 29

Electrical charge

Answer 29

a fundamental property of matter that is described by its amount and as either positive or negative

Question 30

Blueshift

Answer 30

a Doppler shift in which spectral features are shifted to shorter wavelengths, observed when an object is moving toward the observer

Question 31

Rest wavelengths

Answer 31

the wavelength of a spectral feature in the absence of any Doppler shift or gravitational redshift

Question 32

Electromagnetic radiation

Answer 32

another name for light of all types, from radio waves through gamma rays

Question 33

Interferometry

Answer 33

a telescopic technique in which two or more telescopes are used in tandem to produce much better angular resolution than the telescopes could achieve individually

Question 34

Radio waves

Answer 34

light with very long wavelengths- longer than those of infrared light

Question 35

Refracting telescope

Answer 35

a telescope that uses lense to focus light

Question 36

Light pollution

Answer 36

human-made light that hinders astronomical observations

Question 37

Emission

Answer 37

the process by which matter emits energy in the form of light

Question 38

Microwaves

Answer 38

light with wavelengths in the range of micrometers to millimeters

Question 39

Turbulence

Answer 39

rapid and random motion

Question 40

Neutrons

Answer 40

particles with no electrical charge found in atomic nuclei, built from three quarks

Question 41

Absorption

Answer 41

(of light) the process by which matter absorbs radiative energy

Question 42

Electromagnetic wave

Answer 42

a synonym for light, which consists of waves of electric and magnetic fields

Question 43

Atomic mass number

Answer 43

the combined number of protons and neutrons in an atom

Question 44

Reflection/scattering

Answer 44

the process by which matter changes the direction of light

Question 45

Strong force

Answer 45

one of the four fundamental forces; it is the force that holds atomic nuclei together

Question 46

Molecules

Answer 46

technically, the smallest unit of a chemical element or compound

Question 47

Photons

Answer 47

an individual particle of light, characterized by a wavelength and a frequency