Astronomy Chapter 5

Front 1

What does greater warmth entale?

Back 1

greater molecular motion, attributed to the energy of light.

Front 2

What is radiative energy?

Back 2

The energy that carries light

Front 3

What are teh three forms of energy

Back 3

radiative energy
kinetic energy
potential energy

Front 4

What is a joules, what is power? what is a watt?

Back 4

a joules is a unit to measure energy. power is the rate of energy flow, and we measure power in units called wats. 1 watt is equal to one joules

Front 5

Define spectrum

Back 5

the basic colors in a rainbow like spectrum are red, orange, yellow, green, blue and violet, we see white when these colors are mixed in roughly equal proportions. white light contains all the colors of teh rainbow.

Front 6

what is black?

Back 6

it is what we see when there is no light and hense no color.

Front 7

What are the primary colors of vision?

Back 7

red, green and blue. they are the colors directly detected by cells in your eyes.

Front 8

what is cmyk?

Back 8

the artistpalat. cyan, magenta, yellow and black mixed to create a great variety of colors.

Front 9

In which ways can you produce a spectrum of color?

Back 9

a prism or a diffraction grating.

Front 10

what is a diffraction grating.

Back 10

a piece of plastic or glass etched with many closely spaced lines.

Front 11

How do light and matter interact? 4

Back 11

emission absorption transmission and reflection/scattering

Front 12

what is emission?

Back 12

the energy of the light comes from electrical potential energy supplied to the bulb.

Front 13

What is absorption?

Back 13

when you place your hand near an incandescent light bulb your hand absorbs some of the light.

Front 14

Transmission

Back 14

some forms of matter such as glass or air transmit light, which means allowing light to pass through

Front 15

what is reflection/scattering?

Back 15

light can bounce off matter, leading to what we call reflection. scattering is when the bouncing is more random.

Front 16

what are the differences between transparent and opaque?

Back 16

transparent is see through opaque is not. these options are variable.

Front 17

What is vision?

Back 17

your brain interpreting the light.

Front 18

Who provided the first insights into the nature of light?

Back 18

Isaac Newton in 1660's. He did an experiment with two prisms, the first seperated the light, the second put it back together.

Front 19

What are the differences between particles and waves?

Back 19

individual atoms and molecules are particles. they can sit still or can move.

Waves consist of peaks and torughs. (highs and lows) Waves carry energy outward. A particle is a thing while a wave is a pattern revealed by its interaction with particles.

Front 20

what are the three basic properties of waves?

Back 20

wavelength, frequency and speed.

Front 21

what is wavelength?

Back 21

the distance from one peak to the next, or between troughs.

Front 22

What is Frequency?

Back 22

the number of peaks passing by any point each second.

Front 23

What are cycles per second?

Back 23

often called herts, units of frequency.

Front 24

What is speed?

Back 24

tells us how fast the peaks travel across the pond. because a wave carries energy the speed essentially tells us how fast hte energy travels.

Front 25

How do soundwaves travel?

Back 25

through the air causing air molecules to vibrate back and force. the vibrations of matter allow the waves to transmit energy from one place to another.

Front 26

What is waving when a light passes by? what is electric and magnetic fields?

Back 26

A feild discribes the strength of a force that a particle would experience at any given point in space.

electricity and magnetism create forces so their strenght in different places can be described in terms of electic fields and magnetic fields.

Front 27

what is a gravitational field?

Back 27

describes teh strength of gravity at any distance from earth

Front 28

Why is light an electromagnetic wave?

Back 28

vibrations of the electric field in an electromagnetic wave cause any charged partacle to bob up and down.

Front 29

How do you tell the frequency and wavelength between electronmagnetic waves?

Back 29

the distence between peaks tells us the wavelength while the number of times each electron bobs tells us the frequency.

Front 30

What is the speed of light?

Back 30

300,000 kilometers per second

Front 31

How do wavelengths and frequencys interact?

Back 31

because all light travels the same speed and that speed is the wavelength times the frequency, the important relationship between the two is that the longer the wavelength the lower the frequency and vice versa.

Front 32

What are photons?

Back 32

particles of light. Light behaves as both a wave and a particle. light comes in individual pieces called photons that have properties of both particle and waves. each photon is caracterized by a wavelength and a frequency. each photon caries a specific amunt of radiative energy.

Front 33

what is the relationship between radiation and photons?

Back 33

the shorter the wavelength of the light or, the higher the frequency, the higher the energy(radiation) of the photons.

Front 34

What is an electromagnetic spectrum?

Back 34

the complete spectrum of light, including that which we cannot see.

Front 35

what is electromagnetic radiation?

Back 35

light.

Front 36

How is the electromagnetic spectrum divided?

Back 36

gregions, according to wavelength, frequency, or energy. Everything in the spectrum represents a form of light and therefore consists of photons that travel through space at the speed of light.

Front 37

Explain visable light

Back 37

light that is found near the middle of the spectrum that our eyes can see. this liht ranges from about 400 nanometers at the red end

Front 38

what is a nanometer

Back 38

a nanometer is a billionth of a meter

Front 39

what is infared

Back 39

wevelengths somewhat longer than red light that lies beyond the red end of teh rainbow. molecules moving around in a warm object emit infared light.

Front 40

what are radio waves

Back 40

the longest wavelength light. carry so little energy that they have no noticeable effect on our bodies. can make electrons move up and down in an antenna.

Front 41

Microwave

Back 41

where wavelengths range from micrometers to centimeters.

Front 42

What are the shorter wavelengths?

Back 42

ultraviolet, somewhat shorter than blue light. because it lies beyond the blue end of teh rainbow. ultraviolet wavelengths carry enough energy to harm cells in our skin causing sunburn or cancer.

Front 43

what are xrays?

Back 43

light that is even shorter in wavelength than ultraviolet. have enough energy to penetrate through skin and muscle but can be blocked by bones or teeth.

Front 44

what are gamma rays?

Back 44

the shortest wavelength.

Front 45

How do light and matter interact?

Back 45

Light carries information about matter.

Front 46

Who is Democritus?

Back 46

greek philosopher who wondered what would happen if we break a peice of matter , i.e. rock. he claimed that the rock would eventually break into particles so small that nothing smaller could be possible. he called these particles atoms, meaning invisible.

assumed all particles were made up of the four basic elements fire water, earth and air. properties could be explained by physical characteristics.

Front 47

How did democritus view the formation of the world?

Back 47

he imagined the atoms came together to suggest the universe began as a chaotic mix that lowly clumped together.

Front 48

What are elements

Back 48

different types of atoms.

Front 49

Atomic structure. what particles are atoms made up of?

Back 49

protons, neutrons and electrons.

Front 50

what is the nucleus?

Back 50

center of the atom. protons and neutrons are found inside of it.

Front 51

How are the properties of an atom determined?

Back 51

the electricle charge. electricle charge describes how strongly an object will interact with electromagnetic fields.

Front 52

what is an electrical charge?

Back 52

a proton is the pasic unit of a positive charge and an electron is preicisely the opposite. neutrons have no charge. oppositely charged particles attract and similiarily charged particles repel. The attraction between positive and negative is what holds an atom together.

Front 53

how do the electrons surround the neucleus?

Back 53

they give the atom a smeared out cloud that surrounds the nucleus and gives it an apprarent size. give the atom a size far larger than that of its nucleus even though they represent only a tiny portion of the atoms mass.

Front 54

What is atomic number? what is atomic mass number?

Back 54

atomic number is the number of protons in its nucleus. the combined amount of protons and nutrons is the atomic mass. every atom of an element has the exact same number of protons but neutrons may vary.

Front 55

What are isotopes?

Back 55

versions of an element that have different numbers of neutrons.

Front 56

What are molecules?

Back 56

atoms combined. some molecules consist of two or more atoms of the same element.

Front 57

What are phases of matter?

Back 57

solid, liquid, gas

Front 58

what is a chemical bond?

Back 58

the name we give to the interactions between electrons that hold the atoms in a molecule together.

Front 59

what are phase changes?

Back 59

phases of change when one type of bond is broken and replaced by another. these include ptressure, temperature, both. involves the kinetic energy of its particles. as this energy encreses the particles are able to break the bonds holding them.

Front 60

What are phase changes in water?

Back 60

water can be solid, liquid, or gas. low cinetic energy allows them to be tightly bound as a solid ice. always vibrating, the vibrating increases causing melting to turn ice to water. the molecules still have a bond until the energy increases and then they become a gass at 100 degrees celcius.

Front 61

how can the atmosphere have both water and gas phase?

Back 61

tempeture is a measure of teh average kinetic energy of particles in a substence. individual particles may have substantially lower or higher energyies than the average. these molecules may have enough energy to break free of their neighbors and enter the gas phase.

Front 62

sublimation and evaporation

Back 62

sublimation is the process by which molecules escape from a solid, evaporation is the process in which molecules escape from a liquid. higher tempetures lead to higher instances of these.

Front 63

what is molecular dissociation

Back 63

when molecules split into peaices. at higher tempetures the molecules are more violently moving and colisions become so violent that htey can break the chemical bonds.

Front 64

what is ionization?

Back 64

at higher tempetures than dissociation collisions can break the bonds holding electrons around the nuclei of individual atoms. this leads to charged atoms called ions. the process of stripping electrons from atoms is called ionization

the degreeof ionization depends on its temperature and composition. hydrogen has only one electron so can only be ionized once. the remaining hydrogen, h+ becomes a proton, is neutral.

Front 65

What is plasma?

Back 65

a hot gas which seperates h2o into hydrogen and oxygen, where the atoms have broken apart, loosing their charge and become ionized.

Front 66

how are interactions between light and plasma different from a gas consisting of neutral atoms?

Back 66

sometimes referred to the fourth phase of mater. ligitimate to refer to it as a gas.

Front 67

Phases and preasure-- what is pressure?

Back 67

the force per unite area pushing on an objects surface. force is also known as weight.

Front 68

how can preasure affect phases?

Back 68

inner metal core of earth remains solid even though the temperature is high enough that the metal would melt into liquid under less extreme pressure conditions. ex 2. the greater rate of water vapor molecules in our atmosphere the higher rate at which the molecules return to the ocean. helps stabalize water levels.

Front 69

how is energy stored in atoms? how is light produced?

Back 69

to produce light objects must somehow transform energy contained in matter into the vibrations of electric and megnetic fields that we call light.

Front 70

How is light produced?

Back 70

must focus on the charged particles within atom, particularily electrons. Only charged particles can interact with light.

Front 71

in what three ways do atoms contain energy?

Back 71

virtue of their mass, weight.
VIrtue of their motion, kinetic energy

potential energy depends on the arrangement of teir electrons around their nuclei.

Front 72

What is the property of energy stored by electrons in atoms?

Back 72

have only particular amounts of energy, and not other energies in between. like possible hights on a ladder, non adjustable.

Front 73

energy levels?

Back 73

possible energies of an atom

Front 74

how can an electron rise from low energy to a higher one or fall back to a lower energy level?

Back 74

these are called energy level transitions. and occur only when an electron gains or loses the specific amount of energy seperating the two levels. (ladder analogy). Energy seperating levels gets smaller at higher levels. takes more energy to move between level one and two then level two and three.

Front 75

What happens when an electron gains enough energy to reach ionization leve?

Back 75

it escapes the atom completly, thereby ionizing the atom. any excess energy beyond the amoung needed for ionization becomes kenetic energy of the free moving electron.

Front 76

explain quantnized

Back 76

the stabilization and restriction of electron levels to certain levels without the freedom to move between. the study of these level is quantum physics.

Front 77

Define spectroscopy

Back 77

obtaining a spectrum and reading the information it contains

Front 78

intensity

Back 78

amount of energy at each wavelength

Front 79

Continuous spetrum

Back 79

one of the three basic types of spectra- a rainbow of color. spans a broad range of wavelengths without interruption.

Front 80

Emission line spectrum

Back 80

a thin or low density cloud of gas that emits light only at specific wavelengths. consists of bright emission lines against a black background.

Front 81

absorption line spectrum

Back 81

if the light of specific wavelenghts is absorbed the spectrum shows dark absorption lines.

Front 82

Emission lne spectra-- how?

Back 82

Sometiems collisions transfer the right abount of energy to bump an electron from low to high energy level. this cannot be maintainted. when the electron looses this energy it often goes into emitting a photon of light. must have the same amount of energy that the electron looses which means that it always has a specific wavelength and frequency. the bright emmissions correspond to doward transitions of electrons. the rest of the spectrum is dark.

Front 83

absorption line spectra.

Back 83

energy transitions in uppward motion, opposite of emission.

Front 84

What are chemical fingerprints

Back 84

hydrogen emits and absorbs light at specific wavelengths so that we can detect its presence in distant objects. spectrums can show fingerprints left by specific atoms. every atom has its own spectral fingerprint.

Front 85

how are chemical fingerprints useful?

Back 85

they can allow us to measure the tempetures of far off stars.

Front 86

how do molecules produce spectral fingerprints?

Back 86

because hey are made of mor atoms bound together mmolecules can vibrate and rotate. energy changes are usually smaller than those in atoms and produce lower energy photons.

Front 87

what are molecular bands?

Back 87

tightly bunched lines within the spectra of molecular light. usually found in the infared portion of the electromagnetic spectrum.

Front 88

What do looking at spectrums of distant objects tell us?

Back 88

the spectrums of different molecules and atoms will tell us what the object is made out of. more detailed analysis can even tell us the relative porportions of the elements. this is how we have learned the chemical composition of objects thought the universe.

Front 89

What does the reflected light spectra tell us?

Back 89

the mark reflected light leaves on the spectra tells us information about the object. which ever colors are being absorbed represent the colors of what the light is bouncing off of. reflected light gives us the color while absorbed light helps to determine its tempeture.

Front 90

How does light tell us the tmpetures of planets and stars?

Back 90

using the continuous spectra.

Front 91

What are attributes of large or dense objects with light and energy?

Back 91

tend to absorb light across a broad range of wavelengths. light cannot eeasily pass through and light emmitted within cannot easily escape.

by the time photons escape their energies have become randomized so that they are spread over a wide range of wavelengths. this results in a smooth or continuous spectrum, like a pure rainbow withouth any absorption or emission lines.

Front 92

What does the spectrum of a dense object depend on?

Back 92

tempeture. tempeture represents average kenetic energy. the bouncing molecules and atoms end up with energies that match with the energies of teh objects atoms. photon energies depend only on the tempeture of the object.

Front 93

Thermal radiation

Back 93

aka blackbody rdation when the kenetic energies of photons inside an object match the energies of the atoms and molecules within an object. called a thermal radiation spectrum. no real object emits a perfect thermal radiation spectrum. most objects release light that approximates thermal radiation.

Front 94

What are the two laws of thermal radiation?

Back 94

A) Each square metre of a hotter objects surface emits more light at all wavelengths than that of a cooler objects surface.

B) Hotter objects emit photons with a higher average energy, this means a shorter average wavelength.

Front 95

What is the Doppler effect?

Back 95

causes changes in a spectra of distant objects. determines the sound of waves based on the distance between your self and the object emitting the sound.

Front 96

what are wavelengths and frequencys coherts in the doppler effect?

Back 96

frequency is pitch and wavelegth is...

Front 97

How does the doppler effect cause shifts in light?

Back 97

if the object move towards us the light bunches up and so the spectrum is shifted to shorter waveleghts. shorter wavelegths are bluer so an object coming twards us is called a blueshift. longer wavelengths are called redshifts.

Front 98

rest wavelengths

Back 98

wavelengths at stationary clouds or distances.

Front 99

how can you determine speed by using the doppler effect?

Back 99

the shorter the shift of wavelengths becomes, the faster the object is moving towards you. the longer they become, the further away the object is moving from you.

Front 100

how can the doppler effect give us information about motion within an object?

Back 100

rotation will make an object appear wider. parts moving away will be redshift, towards blueshift. the faster the rotation the broader the shift in wavelenghts.

Front 101

1) Watt is a What? Oops, sorry… I meant to ask “What is a Watt?”.
a) A unit of energy.
b) A unit of power.
c) A unit of kinetic energy.
d) That was a terrible joke.

Back 101

a unit of power
A watt is a Joule (a unit of energy) per second (a unit of time). Such a unit describes
what we call power. Written out in terms of meters, kilograms and seconds, this works
out to 1 W = 1 (kg * m2 / s3). a) and c) have units of Joules, and d) is obviously
incorrect. It was an awesome joke.

Front 102

2) What property of light determines its “color”?
a) Wavelength
b) Amplitude
c) Speed
d) Direction

Back 102

The wavelength of a photon determines what color you see. Since the wavelength and
the frequency of light are related through the speed of the photon, and all light goes
the same speed, the frequency could also tell you the color.

Front 103

3) A camera flash appears to be bright white in color. What does this tell you about
the light that was emitted?
a) It is more energetic than high frequency invisible light, like X-rays or UV
radiation.
b) It is composed mostly of white photons.
c) It is high in infrared radiation.
d) It contains a mixture of light from across the visible spectrum.

Back 103

Objects that look black reflect very little visible light, so what we call black is actually
an absence of visible light. Richly hued, colored objects reflect a specific wavelength of
light very strongly, which is why we only see one color of light coming off of them.
White objects reflect (or in this case, a white light source emits) a broad band of colors,
and they all combine to give us white light. There is no such thing as a “white” photon.

Front 104

4) A particle of light (a photon) hits an electron. All of the photon’s energy is turned
into kinetic energy in the electron, and no photons are left after the collision. What
light/matter interaction has taken place?
a) Absorption
b) Reflection
c) Emission
d) Transmission

Back 104

In absorption events, the photon is completely swallowed up by matter. It can be
converted into kinetic energy (where an object speeds up or starts to jiggle), or
electromagnetic potential energy (when an electron absorbs a photon, then moves
further away from a nucleus to a higher energy orbit). If only part of the energy was
absorbed, and the rest left in the form of a photon, this would be a scattering event. If
the photon bounced off of the electron and came back, it would be reflection. If the
electron was moving, then slowed down to make a photon, it would be emission
(emission is the opposite of absorption). If the photon passed right by the electron, we
would say it was transmitted.

Front 105

5) Which of the following is false?
a) When you listen to the radio, you are using your ear to detect radio waves.
b) Humans cannot detect infrared radiation, as it is not in the visible spectrum.
c) The sun is similar to a black body, so we can tell its temperature from its
spectrum.
d) Most of the volume of an atom is composed of empty space

Back 105

Your ear does not detect radio waves. Radio waves are electromagnetic waves with a
very long wavelength, which we use to transmit information through the air. This
information is then interpreted by your radio, and converted into sound waves
(pressure waves that travel through air).

Front 106

6) Which of the following phases of a material is the hottest?
a) Liquid
b) Plasma
c) Solid
d) Gas

Back 106

If kept at the same pressure, a solid material will normally melt into a liquid, then boil
into a gas, then start having its electrons stripped away (making it a plasma) as its
temperature increases. Some materials skip a step, however. Carbon dioxide (CO2) is
called “dry ice” in its solid form (around -80ºC at normal pressures). When you heat it
up, it skips the liquid stage altogether and becomes a gas. This is known as

Front 107

7) A transparent material
a) Absorbs light very well.
b) Scatters light very well.
c) Transmits light very well.
d) Reflects light very well.

Back 107

A transparent material like glass allows most photons of visible light through without
affecting them (transmission). An opaque material blocks most of the light, either by
reflection or absorption.

Front 108

8) Why is grass green?
a) It absorbs green light and emits all other colors
b) It transmits green light and absorbs all other colors
c) It reflects green light and absorbs all other colors
d) It scatters green light

Back 108

If a) were true, and grass emitted its own light, it would glow even if there was no
sunlight illuminating it (things like glow sticks and light bulbs emit light, non-glowing
objects only reflect light that you shine on them). If b) were true, grass would look
green, but would also be transparent

Front 109

9) An atom is missing an electron in one of its electron energy levels, and another
electron moves in to fill the space. Which transition would emit the most energetic
photon?
a) An electron drops in energy from the 4th energy level to the lowest (first) energy
level.
b) An electron drops in energy from the 4th energy level to the 3rd energy level.
c) An electron rises in energy from the first energy level to the 4th energy level.
d) An electron rises in energy from the 3rd energy level to the 4th energy level.

Back 109

If the electron drops in energy, that energy has to go somewhere. You can’t create or
destroy energy; you can only change its form. In this case, the lost energy becomes a
photon. The more energy the electron loses, the more energy the photon has. The most
energy is lost when the electron takes the biggest step down, so the answer is a).
If the electron gains energy, that energy has to come from somewhere. It can only do
this if it absorbs a photon.

Front 110

10) You are looking at a tungsten lamp, which emits a very smooth, continuous
spectrum in the wavelengths you are looking in. Suddenly, a dense cloud of
hydrogen passes between you and the lamp. How does the spectrum change?a) You start to see hydrogen emission lines.
b) You start to see tungsten emission lines.
c) You start to see hydrogen absorption lines.
d) You start to see tungsten absorption lines.

Back 110

The light emitted by the tungsten will be absorbed by the hydrogen (if it is at a
wavelength corresponding to a hydrogen transition). Therefore you’ll see dips in the
spectrum at those wavelengths, as not much of that light is making it through. The
photons that don’t meet the hydrogen transmission requirements will just pass
through.

Front 111

11) Which effect makes emission lines from far away galaxies look redder than they
should, and why?
a) The Doppler effect; the galaxies are receding from us, so their light looks redder.
b) The Doppler effect; the galaxies are approaching us, so their light looks redder.
c) Absorption; hydrogen absorbs then re-emits their light in the “red” wavelength
range.
d) Scattering; light from far away galaxies scatters off interstellar hydrogen,
reddening it.

Back 111

Most galaxies are rapidly receding from us. Because of this, the light that they emit
seems to be stretched out. This corresponds to a longer wavelength, which makes light
shift towards the red side of the visible spectrum. How much it shifts depends upon the
speed at which the galaxy is running away.

Front 112

12) You find an ion of a rare isotope of the (hitherto undetected) element
Unobtanium while on a family vacation to Pandora. The nucleus of this isotope has
215 protons and 285 neutrons, and it has 213 electrons surrounding it. Which of the
following are the correct atomic number, weight and charge (in that order)?
a) 215, 500, -2
b) 500, 215, -2
c) 500, 215, +2
d) 215, 500, +2

Back 112

The atomic number is simply the number of protons (here, 215), and the atomic weight
is the number of protons plus the number of neutrons (215 + 285 = 500). The charge
will be +1 for every proton, -1 for every electron, so the charge is 215-213=+2.