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SCIENCE 3
Module 2
2.01FORMATION OF HEAVENLY BODIES
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Big Bang
The formation of the universe started with the Big Bang.
Clouds of Dust
After the Big Bang, the universe contained pockets of dust.
Dust Starts to Condense
The Law of Universal Gravitation says that all objects
attract each other. Because of this, the pockets of dust
started to attract to each other. The dust then became more
packed together. You can think of this idea kind of like a
spiral. The center of the spiral is closely packed and it gets
less packed as you move away from the center.
Planet or Star is formed
Eventually the dust clouds became so packed they formed a
planet or star. Large clouds of dust became stars and
smaller clouds became planets.
02.01 FORMATION OF HEAVENLY BODIES GRAVITY CREATES STARS
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They postulated that the life cycle of a star is
dominated by a single factor ...(long pause).. gravity.
Gravity is significant at the birth of a star. Stars are
born in giant nebulae when, under the pull of gravity,
its gases begin to coalesce in areas here and there. It
is the beginning of a process which will last several
million years, and during which, evermore matter is
collected until, eventually, a sphere of gas begins to
take form. As mass increases, so does gravity. It
compresses the gas at the center of the embryonic
star and that heats it up until it becomes
incandescent. Once the interior temperature reaches
15 million degrees Centigrade the nuclear fusion
process begins with hydrogen being converted into
helium.... ...and a star is born.
2.02 GALAXIES
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The Universe is Huge
A galaxy is a group of stars, planets, gas, and dust
that is held together by gravity.
Our galaxy, The Milky Way, is thought to have
around 100,000,000,000 stars and there is thought to
be about 100,000,000,000 other galaxies in the
Universe. That leaves the universe with trillions and
trillions of stars!
Many scientists estimate that the universe has
400,000,000,000,000,000,000,000. stars.
Let’s take a second to talk about how big this number
really is. It is important to understand the magnitude
of how many stars this is for you to really understand
the size of galaxies and the universe.
2.02 GALAXIES
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Types of Galaxies
There are three different types of galaxies. Watch the
presentation below to learn about these different types of
galaxies.
There are three types of galaxies:
Spiral:
Spiral galaxies revolve around a single point. Our galaxy,
the milky way is an example of a spiral galaxy.
Elliptical:
Elliptical galaxies are circular in shape. Most of the objects
in an elliptical galaxy are concentrated around the center
of the galaxy. From far away these galaxies look like one
big star.
Irregular:
Irregular galaxies are galaxies that are not spiral or
elliptical. These galaxies have an irregular shape.
2.02 GALAXIES
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Galaxies and stars
The names of the different types of galaxies describe the shape of the galaxy.
The type of the galaxy can also tell us about the age of the stars and the
amount of space dust in the galaxy.
Irregular Galaxies
Irregular galaxies are young galaxies. Because of this, they contain mostly
young stars. These galaxies have many stars that are still forming.
Irregular galaxies also contain lots of gas and dust. This gas and dust can form
into new stars or planets.
Spiral Galaxies
Spiral galaxies are medium aged galaxies. Because of this, they contain some
older stars and some younger stars. They still have a few stars that are still
forming.
Spiral galaxies also contain some gas and dust. This gas and dust could
condense to form new stars and planets.
Elliptical Galaxies
Elliptical galaxies are old galaxies. Because of this, they contain mostly old
stars and they do not have new stars forming.
Because elliptical galaxies do not have new stars forming, they do not have
much gas and dust.
2.03 DISTANCES IN SPACE
Cool Graphics for your Presentation….
2.03 DISTANCE IN SPACE
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Speed of Light
Have you ever noticed that during a thunderstorm you can
see the lightning a long time before you hear the thunder?
The reason for this is light travels 800,000 times faster
than sound. In fact, light is the fastest thing in the
universe that we know of.
How long do you think it will take light to travel the
following distances?
To Earth-0.13 sec.
To Moon- 1.3 sec.
To Sun- 8 min.
Other than the sun, the nearest star to us is called Proxima
Centauri . It takes light 4.2 years to travel from this star
to our eyes. Think about how fast light is. Proxima
Centauri must be very far away for light to take 4.2 years
to travel from its surface to the earth!
2.03 DISTANCE IN SPACE
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Light Years
Because light is so fast, it is used to measure
distances in space.
A light year is the distance that light can travel in
one year. So if an object is one light year away, it will
take light one year to get there.
1 light year = 9,461,000,000,000 km or
5,879,000,000,000 miles
Light years are used to measure distances in space
because their large size allows us to talk about vast
distances using smaller numbers. For instance, it is
much easier to talk about three light years, than it
would be to talk about 17637000000000 miles!
2.04 PROPERTIES OF STARS
Star Size
 Scientists use four different characteristics to
help them classify and describe stars.
 Neutron Star
 A neutron star is the smallest type of star.
Neutron stars have a diameter that is about 10 to
20 km. This is probably less than the total
distance that you travel on a daily basis.
 Even though Neutron Stars are very small, they
are very massive. One teaspoon of a Neutron Star
would weigh about 10 million tons. These stars
are very tight and compact.
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2.04 PROPERTIES OF STARS
Dwarf Star
 Dwarf stars are stars that are about the same
size as the Earth, but they weigh as much as the
Sun. Dwarfs are not as compact as Neutron stars.
A teaspoon of a Dwarf Star would weigh 5 tons.
 Medium-sized Star
 The majority of the stars in the universe are
medium-sized stars. Medium-sized stars are
about the same size as the Sun. The Sun is a
medium-sized star.
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2.04 PROPERTIES OF STARS
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Giant Star
Giant stars are stars that are 10 to 1000 times bigger
than the sun. The following image is of a red giant
star called Mira A. It is sometimes called Mira’s
Football because of its football like shape. This star is
700 time bigger than the sun.
Supergiant Star
A supergiant star is a star that is more than 1000
times bigger than the sun. Below is a picture of
Betelgeuse. Betelgeuse is a supergiant that can be
seen with the naked eye in the night sky.
If we were to replace our sun with Betelgeuse as the
center of our solar system, it is so big that it would
extend past the orbit of Jupiter.
2.04 PROPERTIES OF STARS
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Star Brightness
Imagine that you had a small candle and a big spotlight. If a friend held these
about ten feet from you, which of these would be the brightest? The spotlight
right? Now imagine the candle is ten feet from you and the spotlight is one mile
away from you. Which one would be brighter? The candle would appear
brighter. This helps to illustrate that there are three things that affect star
brightness.
The distance light source is from your eye.
The size of the light source.
The strength of the light source.
Since not all stars are the same distance from your eye, size, or strength, every
star will have a different brightness when you look up into the night sky. The
brightness of a star as it appears from the earth, without the effect of the
earth’s atmosphere, is called apparent magnitude . Since the earth’s
atmosphere causes stars to look different, the apparent magnitude takes this
effect out.
If we could take two stars and put them side by side, we could tell easily which
star is brighter because they are the same distance from your eye. Absolute
magnitude is the amount of light that a star gives off.
Both apparent and absolute magnitude are important when studying stars.
2.04 PROPERTIES OF STARS
Star Temperature
 Every star has a different temperature. The
temperature of the stars can be different based
on the size of the star and the type of elements
that make up the star.
 The temperature of a star is very important
because it determines the color of the star. Roll
over the temperatures below to see how the
temperature and star color are related.
 Cool Star – Red/ Orange
 Warm Star- Yellow
 Hot Star-White
 Very Hot- Blue
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2.04 PROPERTIES OF STARS
Star Composition
 By studying the light that comes off stars,
scientists can determine what the star is made of.
Every star gives off a different fingerprint of light
and this light gives scientists a clue as to what
elements are located in the star.
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The most common element in stars is hydrogen.
The second most common element in stars is
helium. Stars do contain other elements but
these two are the most common.
2.04 PROPERTIES OF STARS
2.04 PROPERTIES OF STARS REVIEW
Supergiant- More than 1000 times bigger then
the sun
 Giant- 10 to 1000 times bigger then the sun
 Medium Size- Majority of the stars in the
universe are Medium size. About the size of the
sun. The sun is a medium size star.
 Dwarf- About the size of the earth but weight
about as much as the sun.
 Neutron Star-Smallest star that is very tight and
compact. Diameter of about 10 to 20 km.
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2.04 PROPERTIES OF STARS REVIEW
The Four Characteristics of Stars
Temperature - Determines the color of the star
Star composition-Provides a "fingerprint" for stars
Star Brightness- Is determined by star size,
distance away, and strength of light
Star Size-Dwarf, medium, giant and supergiant
2.04 PROPERTIES OF STARS REVIEW
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Apparent Magnitude- The brightness of a star
as it appears from the earth, without the effect of
the earth’s atmosphere
Absolute Magnitude- the amount of light that
a star gives off. (brightness)
2.05 HR DIAGRAM
The main reason that the HR Diagram is so
useful is you can tell the size of the star by
plotting it on the HR Diagram. The different
sizes of stars form a pattern on the HR diagram.
 The HR diagram is a graph with the Absolute
magnitude on the y – axis. Absolute magnitude is
measure in comparison to the sun. Absolute
magnitude is the brightness of a star as
compared to the sun. We assign the sun an
absolute magnitude of 1.
 The temperature on the x-axis. The Surface
temperature of the sun is measured in degrees
Celsius.
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2.06 LIFE CYCLE OF STARS
Stages of a Stars Life
Protostar – The birth of a star
Fusion Ignition to Main Sequence – Infancy to
Childhood ages
2.06- LIFE CYCLE OF STARS
Red Giant or Supergiant- Middle age stars
Dwarf or Black Hole- Old age to Death of a star
2.06LIFE CYCLE OF STARS
Protostar-Fetus
 A nebula is a region of gas and dust in space.
Over time the gas and dust collects in a spinning
cloud. This condenses more to from a protostar.
 A protostar is the birth place of a star. It is
similar to the fetus stage in the human life cycle.
 Fusion Ignition/Main Sequence=Infancy and
Adult
 As the gases in a protostar become more and
more compact, the pressure and heat will get to a
point where the gas will ignite and a star is born.
The main sequence is when the star is in its
youth. These stars are of average size.
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2.06LIFE CYCLE OF STARS
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Red Giant/Red Supergiant- Middle Age
After a star has burned for awhile, it will become a
giant or supergiant. Giants and supergaints are stars
that are middle aged.
Black Hole/Dwarf-Old Age/Death
At the end of a stars life, it will become a dwarf or a
black hole. The giants will turn into dwarfs and the
supergiants will turn into blackholes.
Black Holes
A black hole is formed when a supergiant star dies.
Black holes are hard for scientists to study because
they are black and hard to see. Select to Open
Fun Fact:
It is estimated that a 100 lb person would weigh
9,200,000,000,000 lbs on a black hole.
2.06 ADVANCE: MASS DETERMINES FATE
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Betelgeuse started like every star.
A nebula condensed into a protostar.
The protostar formed a main sequence star.
The main sequence star turned into the supergiant
that we see today.
Since Betelgeuse has so much mass, it will soon
explode in a giant supernova . When the gravity of
supergiants gets too big, the star will explode. This is
called a supernova.
After stars explode in a supernova, they have two
options to spend the rest of their life. Again
depending on the mass left after the supernova, the
star will either become a neutron star or a black hole.
High mass stars will become neutron stars.
Extremely high mass stars will become black holes.
2.06 ADVANCE: MASS DETERMINES FATE
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Fate of an Average Sized Star
A nebula condensed into a protostar
The protostar formed a main sequence star
The sun is currently a main sequence star. More
specifically the sun is in the middle of its main
sequence stage. At some point in the future, the sun
will end its main sequence stage and it will begin to
swell to form a red giant. When this happens the sun
will swell all the way out to the orbit of Jupiter. All
the inner planets will be destroyed. Don’t worry this
won’t happen for a very long time.
After the sun becomes a red giant, it will then expel
its outer shell of gas and form a planetary nebula.
The gases that are let off by the sun glow with all
sorts of brilliant colors. The planetary nebula stage
only lasts a few thousand years.
2.06 ADVANCE: MASS DETERMINES FATE
Planetary nebula will eventually collapse into a
white dwarf.
 Once white dwarfs have all burnt out, it is
thought that they will form a black dwarf. At this
point there are not black dwarfs found in our
universe. The reason for this is our universe is
not old enough and there has not been a white
dwarf that has burn out yet. At some point in the
future, a white dwarf will burn out and possiblity
for a black dwarf to form will happen.
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2.06 ADVANCE: MASS DETERMINES FATE
High mass stars will not live as long as low mass
stars.
 The high mass stars will be hotter and brighter.
Because of this they will burn through their fuel
faster.
 Small mass stars will live for 100 billion years.
 Average mass stars will live for 10 billion years.
 Large mass stars will live for 5 billion years or
less.
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2.07 SOLAR PROPERTIES
Solar prominences are flame-like arcs into
space, which are associated with sunspots and
magnetic fields. Some solar prominences last for
many days, others for only minutes.
 Solar Flares- Flares, of all solar events, are the
shortest…lasting only minutes..(pause).. and the
most violent… creating a fusion explosion equal
to millions of hydrogen bombs. The explosion of a
solar flare is so violent that, like an earth quake,
pressure waves race across the entire immense
surface of the sun in just a few hours.
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2.07SOLAR PROPERTIES
Sunspots-If you were to look at the surface of
the sun through a solar telescope, you would see
areas of dark spots. These are sunspots. These
regions are dark because the temperature within
a sunspot is lower than the rest of the sun. Over
time these sunspots will come and go.
 Even though the sun is so far away, these
sunspots can have an effect to us on earth. When
there are a large number of sunspots, the
magnetic activity that comes from these sunspots
can disrupt communication systems on earth.
Cell phones, radios, and TV antennas will not
work as well.
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2.07SOLAR PROPERTIES
Corona-The corona is the outermost part of the
suns atmosphere. The temperature of the corona
exceeds one million ºC.
 The corona can only be seen during an eclipse,
where the moon covers up the sun leaving only
the corona exposed, or through a special solar
telescope.
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ELECTROMAGNETIC SPECTRUM
2.08 ELECTROMAGNETIC SPECTRUM
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Electromagnetic Spectrum-the part of light that we can see is only
a small part of light. The electromagnetic spectrum is the range for
light.
The frequencies visible to us, we see as this range of colors.
All visible frequencies mixed together appear as white light until
separated by a prism.
The color of objects comes from the balance of frequencies in the light
striking them.
The frequencies the objects absorb and finally, the non-absorbed
frequencies they reflect, which we call their color.
Beyond the light visible to humans, are ultra-violet frequencies
visible to insects:
and infra-red waves, that snakes can sense,
and weather satellites too.
Radio waves- coming from matter deep in outer space, that radio
telescopes can picture and x-rays that easily pass right through a
body revealing structures deep inside a living person and so the
frequencies the human eye can see, have been vastly expanded by
technology from just visible light, to the entire range of the electromagnetic spectrum.
2.08 ELECTROMAGNETIC SPECTRUM
Gamma Rays
 Description: Gamma rays are light that is given
off of radioactive substances.
 X-rays
 Description: X-rays are light that is used in the
medical field to look at people’s bones and insides
 Ultraviolet Light
 Description: Ultraviolet light is radiation that is
given off by the sun that causes sunburns.
 Visible Light
 Description: Visible light is all the light that
humans can see.
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2.08ELECTROMAGNETIC SPECTRUM
Infrared Light
 Description: Infrared light is heat. The military
uses infrared to see how many people are in
buildings or to see people at night.
 Microwaves
 Description: Microwaves are light that is used in
radar and to heat up our food.
 Radio Waves
 Description: Radio waves are light that is used
for radio, TV antennas, and cell phones.
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2.08 ELECTROMAGNETIC SPECTRUM
:REVIEW
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2.
All of the following are types of light except
Visible light
Microwaves
Plasma
X-rays
The electromagnetic spectrum is
A magnetic field.
A device that puts out a magnetic field.
The study of electricity.
The range of all the types of light.
2.08 ELECTROMAGNETIC SPECTRUM
REVIEW
3. Which of the following types of light can
humans see with their eyes?
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Microwaves
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Radio Waves
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Gamma rays
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Humans cannot see any of the above
with their eyes.
 4. Which colors are contained in white light?
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All of the colors
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No colors
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All the light colors
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All the dark colors
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2.08 ELECTROMAGNETIC SPECTRUM
REVIEW
5. Which type of light can cause sunburns?
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Visible Light
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Ultraviolet Light
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Infrared Light
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X-rays
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2.08 ELECTROMAGNETIC SPECTRUM
REVIEW
Heat is what type of light?
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Visible Light
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Ultraviolet Light
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Infrared Light
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Gamma Rays
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Which type of light transmits cell phone
conversations?
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Radio Waves
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Ultraviolet Light
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Infrared Light
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Gamma Ray
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6.
2.08 ADVANCE: CHARACTERISTICS OF
LIGHT
Where does sound fit in? This is a great question!
And though the electromagnetic spectrum
includes various types of radio waves to
broadcast sound, sound is not part of the
electromagnetic spectrum.
 Sound is a totally different form of energy than
light represented by the electromagnetic
spectrum. The biggest difference is that all types
of light can travel through empty space, while
sound requires matter to travel through, like air
or water. Isn't that cool?
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2.08 ADVANCE: CHARACTERISTICS OF
LIGHT
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Light is a Wave
Light behaves in two ways - like a wave and like a
particle. With this in mind, we learned that there are
more kinds of light than just what you can see. There
are many different types of light, but what
determines the kind of light? There are two properties
of light that will determine the type of light.
Wavelenght-is the distance between two wave crest
Frequency-is the number of times a wave crest
passes by one point in one second.
Light does not travel in a perfectly straight line. It
moves like a wave does on the ocean. There are two
important properties of waves that determine the
type of light. Explore the properties to learn more
about them.
2.08ADVANCE: CHARACTERISTICS
LIGHT
OF
Wavelength and Frequency are Related
 When we say that wavelength and frequency are
related, that does not mean that they are
brothers or sister. It means:
 if you change the wavelength of a wave it will
affect the frequency,
 if you change the frequency of a wave it will
affect the wavelength.
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2.08ADVANCE: CHARACTERISTICS
LIGHT
OF
These two different waves show:
 when the wavelength increases, the frequency
will decrease,
 when the wavelength decreases, the frequency
will increase.
 Wavelength and frequency are opposites.
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2.09 LIGHT: FINGERPRINT OF STARS
Emission Spectrum
 The light “fingerprint” is called an emission
spectrum . When an atom lets off or emits light
it does not let off just one color. It emits a
combination of a few colors. The emission
spectrum is all the colors that the atom emits.
Here is the emission spectrum for iron.
 Spectroscopes are the instruments that
scientists use to see the atoms emission
spectrum. They take the light and bend it
through a prism. Spectroscopes take the light
coming off objects and break them down into
their colors.
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2.09LIGHT: FINGERPRINT OF STARS
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Stars and planets are made up of many different
atoms. When scientists pass the light coming
from the star or planet through the spectrometer
they get an emission spectrum. We can compare
this emission spectrum to a situation where
many people have put their fingerprints in the
same spot. The scientist is like a police officer
that has to sort them all out.
2.09LIGHT: FINGERPRINT OF STARS
Review Spectrum
 White Light
 White light is light that contains every color of
the rainbow. Notice that every color is in white
light’s emission spectrum.
 Hydrogen
 Hydrogen’s spectrum has some different shades
of violet, some shades of blue and a red.
Hydrogen is the most abundant element in the
universe.
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2.09LIGHT: FINGERPRINT OF STARS
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Sodium
Sodium’s spectrum contains two shades of yellow.
Helium
Helium is another very abundant element in the
universe. Helium’s spectrum contains some different
shades of blues, a yellow and a red.
Neon
Neon is the atom that is contained in a neon light.
Can you see why a neon light looks orange?
Mercury
Mercury’s spectrum contains purple, blue, green and
two shades of yellow.