Using Emission Spectra to Determine What Stars are Made Of

Summary

The video script dives into the fascinating world of spectroscopy, a technique that allows scientists to determine the composition of stars without physically sampling them. It explains that stars, like our Sun, are made of gas that emits light, and by analyzing the light through a spectroscope, we can identify the unique emission spectra of different elements. The video uses examples of emission spectra from hydrogen, helium, nitrogen, and other elements to illustrate how each element has a distinct spectral fingerprint. It then applies this knowledge to reveal the composition of our Sun, which contains hydrogen and helium, and further explores the emission spectra of other stars to identify their elemental makeup. The script also highlights the broader applications of spectroscopy in understanding the composition of planets like Jupiter, nebulae like the Orion Nebula, and even entire galaxies. It concludes by emphasizing the dominance of hydrogen and helium in the universe, as revealed through spectroscopic studies.

Takeaways

• 🌞 The Sun is our nearest star and it plays a crucial role in powering photosynthesis, driving weather processes, and illuminating our days.
• 🌌 There are countless stars in the universe, with only a fraction visible to us at night, and scientists use spectroscopy to determine their composition.
• 🔬 Spectroscopy is the study of light, allowing us to observe and analyze the light emitted by stars to understand what they are made of.
• 🤔 Stars are made of gas, primarily hydrogen, which can be demonstrated through experiments with glowing gas tubes.
• 🌈 An emission spectrum is a pattern of light that can be split into its component colors, which is unique to each element.
• 🚀 By comparing a star's emission spectrum to known emission spectra of elements, scientists can identify the elements present in a star.
• 🔍 The Sun's emission spectrum reveals the presence of hydrogen and helium, which are its main components.
• 🌟 Star A's emission spectrum contains hydrogen and lithium, Star B contains carbon and helium, and Star C contains oxygen and helium.
• 🌈 Star D's spectrum is more complex, containing carbon, helium, and hydrogen, while Star E contains oxygen, carbon, and helium.
• 🌠 Star F's spectrum, the most challenging, reveals the presence of nitrogen, helium, and hydrogen.
• 📚 Spectroscopy has been instrumental in understanding the composition of our solar system's planets, nebulae, and even distant galaxies.
• 📊 The universe is predominantly composed of hydrogen and helium, with trace amounts of other elements like oxygen and carbon.

Q & A

What is the primary source of energy for life on Earth?

The primary source of energy for life on Earth is the Sun, which provides light energy that powers photosynthesis in plants and drives weather processes.

How do scientists determine the composition of stars if it's impossible to take a sample?

Scientists use spectroscopy, the study of light, to determine the elements that make up stars by analyzing the light emitted by these celestial bodies.

What is an emission spectrum and how is it used to identify elements in stars?

An emission spectrum is a pattern of bright colored lines produced when light is split up into its component colors. Each element has a unique emission spectrum, which can be used to identify the elements present in stars by comparing the observed spectrum with known emission spectra of elements.

What is the significance of the emission lines in an emission spectrum?

Emission lines in an emission spectrum are significant because each line corresponds to a specific element. By identifying these lines, scientists can determine which elements are present in a star.

How does the color of the light emitted by a glowing gas relate to its composition?

The color of the light emitted by a glowing gas is related to its composition because different elements emit light at different wavelengths, resulting in different colors. This is used in spectroscopy to identify the elements.

What elements are most abundant in the universe according to spectroscopic analysis?

According to spectroscopic analysis, the most abundant elements in the universe are hydrogen and helium, with hydrogen being the most prevalent.

How does the emission spectrum of a star differ from that of a gas discharge tube?

The emission spectrum of a star is more complex than that of a gas discharge tube because a star's spectrum is composed of the combined emission spectra of all the elements present in the star, while a gas discharge tube typically contains only one or a few elements.

What are some of the elements that can be identified in the Sun's emission spectrum?

Some of the elements that can be identified in the Sun's emission spectrum include hydrogen and helium, which are the most abundant elements in the Sun.

How does spectroscopy help in understanding the composition of distant celestial objects like galaxies?

Spectroscopy helps in understanding the composition of distant celestial objects like galaxies by analyzing the light they emit. The presence of certain elements can be inferred from the characteristic emission lines in their spectra, allowing scientists to draw conclusions about their composition.

What is the role of spectroscopy in determining the composition of planetary atmospheres?

Spectroscopy plays a crucial role in determining the composition of planetary atmospheres by analyzing the light that passes through or is emitted by the atmosphere. The presence of different elements and compounds can be identified through their unique emission or absorption spectra.

Outlines

00:00

🌟 Understanding Stars Through Spectroscopy

The video begins with an introduction to the sun as our nearest star, which is vital for life on Earth by providing light and heat. It explains the challenge of determining the composition of stars, which are far away and presumably very hot, making it difficult to take samples. The main tool for this task is spectroscopy, which is the study of light. The video demonstrates how different elements, such as hydrogen and helium, produce unique emission spectra when they are glowing. By using a spectroscope, one can split light into its component colors and identify the elements present in a star by matching the observed spectrum with known emission spectra of elements.

05:00

🌌 Identifying Elements in Stars Using Emission Spectra

The video continues by illustrating how scientists use the emission spectra of known elements to identify which elements are present in stars. It provides examples of emission spectra for the sun and other stars, showing how the presence of hydrogen and helium can be detected. The video emphasizes that to confidently identify an element, every individual emission line associated with that element must be present in the observed spectrum. It also discusses how the technique of spectroscopy has been used to study the composition of other celestial bodies, such as Jupiter and the Orion Nebula, and even to estimate the composition of the entire universe, which is predominantly made of hydrogen and helium.

10:01

🔍 Advanced Spectroscopy: Pinpointing Elements in Star Spectra

The third paragraph delves into more complex examples of emission spectra, challenging viewers to identify multiple elements within the spectra of different stars. It demonstrates how stars can be composed of various elements, such as carbon, oxygen, nitrogen, and others, in addition to hydrogen and helium. The video highlights the importance of persistence and careful analysis when using emission spectra to identify elements in stars. It concludes by reiterating the goal of the video, which is to enable viewers to use spectroscopy to determine the elements that make up a star, and encourages revisiting the video for better understanding if needed.

Keywords

💡Sun

The Sun is the star at the center of the Solar System and the nearest star to Earth. It provides light energy that powers photosynthesis in plants, drives weather processes, and illuminates our day. The video emphasizes the Sun's importance by discussing how scientists use spectroscopy to determine its composition, which is primarily hydrogen and helium.

💡Stars

Stars are celestial bodies made primarily of gas that emit light and heat due to nuclear fusion reactions in their cores. The video explores the concept of stars, highlighting that there are trillions of them in the universe, and discusses how their composition can be analyzed through spectroscopy.

💡Spectrometry

Spectrometry is the technique used to study the interaction of electromagnetic radiation with matter. In the context of the video, it is used to determine the composition of stars by analyzing the light they emit. The video explains how spectroscopy allows scientists to identify elements in stars by looking at their emission spectra.

💡Emission Spectrum

An emission spectrum is a record of the spectrum of light emitted by a substance when it is heated. The video demonstrates how each element has a unique emission spectrum with specific emission lines that can be used to identify the elements present in a star.

💡Hydrogen

Hydrogen is the lightest and most abundant element in the universe, and it is the primary component of stars, including our Sun. The video uses hydrogen as an example to illustrate how the light from a glowing gas (hydrogen) can be analyzed to determine its composition.

💡Helium

Helium is the second lightest element and is also a significant component of stars. The video mentions helium as one of the elements found in the Sun's emission spectrum, highlighting its presence in stars through spectroscopic analysis.

💡Gas Discharge Tubes

Gas discharge tubes are used in the video to demonstrate how different gases, when excited, emit light at specific wavelengths, resulting in unique emission spectra. These tubes are filled with gases like hydrogen and helium and are used to show how the light from these gases can be split into their component colors using a spectroscope.

💡Nitrogen

Nitrogen is a diatomic gas that makes up about 78% of Earth's atmosphere. In the video, nitrogen is identified as one of the elements in the emission spectrum of a star, demonstrating how spectroscopy can reveal the presence of elements in celestial bodies.

💡Carbon

Carbon is a chemical element that is crucial for life on Earth. The video discusses carbon as one of the elements that can be identified in the emission spectra of stars, showing that it is not only present on Earth but also in the cosmos.

💡Lithium

Lithium is a lightweight metal that is represented in the video as one of the elements found in the emission spectrum of a star. Despite its simplicity, lithium's emission lines can be challenging to identify in complex spectra, but they are still detectable through spectroscopy.

💡Oxygen

Oxygen is essential for life on Earth and is also found in stars. The video uses oxygen as an example of an element that can be identified in the emission spectra of stars, emphasizing the universality of this element.

💡Composition of the Universe

The video concludes with a discussion on the composition of the universe as a whole. It states that the majority of the universe is made up of hydrogen and helium, with trace amounts of other elements like oxygen. This conclusion is reached through the use of spectroscopy to analyze the light from various celestial bodies.

Highlights

The sun is our nearest star and provides the energy for photosynthesis, weather processes, and daylight.

Stars are made of gas and emit light, and scientists use spectroscopy to determine their composition.

Spectrometry is the study of light, allowing scientists to view and observe the elements that make up stars.

Experiments with glowing gas, such as hydrogen, can help us understand the composition of stars.

A spectroscope can split light into its component colors, revealing an element's unique emission spectrum.

Different elements produce unique emission spectra, which can be used to identify them in stars.

The sun's emission spectrum reveals the presence of hydrogen and helium.

Emission lines in a star's spectrum can be compared to known element spectra to identify their composition.

Star A's emission spectrum contains hydrogen and lithium.

Star B's spectrum reveals the presence of carbon and helium.

Star C contains oxygen and helium, as identified through its emission spectrum.

Star D's complex emission spectrum includes carbon, helium, and hydrogen.

Star E's emission spectrum shows the presence of oxygen, carbon, and helium.

Star F's tricky spectrum contains nitrogen, helium, and hydrogen.

Spectroscopic analysis of Jupiter's atmosphere reveals it is mostly composed of hydrogen and helium.

The Orion Nebula's composition can be determined through spectroscopy, showing hydrogen, oxygen, and ionized sulfur.

Spectroscopic studies of the Andromeda galaxy reveal the presence of carbon dust and hydrogen gas.

The universe is predominantly composed of hydrogen and helium, with trace amounts of other elements.

The goal of the video is to teach viewers how to use spectroscopy to determine the elements that make up a star.

Transcripts

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the sun is our nearest star

it provides the light energy that powers

photosynthesis

in plants its heat drives

pretty much every weather process

and of course it provides the light that

illuminates our day

and the sun is not the only star out

there

there are trillions and trillions of

other stars in the universe

a small small fraction of which are

visible to us at night time

but what is a star such as our sun made

of being very far away and presumably

very hot

it's hard to see how you could take a

sample of the sun's material this is

probably impossible

so how do scientists figure out what the

sun

is made of and this is in fact the goal

of this video we want to be able to use

spectroscopy

to determine the elements that make up a

star

and spectroscopy is just a term for the

study of light

spectro means light or color and scopy

means to view or

observe

so in this video we're learning about

stars now there's probably a couple of

assumptions we can make right now

one of them is that stars are made out

of gas you've probably heard that before

and the other is that stars emit light

they're literally balls of glowing gas

well i have the ability here to actually

produce some glowing gas

and we might be able to figure out

something about stars by investigating

our glowing gas

this is a power source and here i have a

tube

this tube has two metal contacts on the

end and it's filled with a gas

the gas this tube contains is hydrogen

it's element number one on the periodic

table so let's plug that in

and flip the switch

that is a glowing gas a little bit like

the glowing gas that a star might be

made out of

now would you believe me if i told you

that you could take the light

from that glowing gas and figure out

what colors it's made out of

you can split it up into its component

colors

well to do that we can use an instrument

called a spectroscope

let's take a look and see what the

spectroscope tells us about the light

from this glowing hydrogen gas

look at that so our spectroscope can

split up the light from hydrogen

into its component colors each of these

bright

colored lines is called an emission line

and this is the emission spectrum for

hydrogen

let's take a look at a couple of other

elements

the gas in this emission tube is helium

this is element number two on the

periodic table

notice right away that glowing gas is a

different color

all right that is the emission spectrum

for

helium gas notice that the emission

spectrum is completely different

the emission lines are different

brightnesses different colors

in different places

here's the emission spectrum for

nitrogen gas

here's neon

argon

and mercury

so we see that each different element

gives us

a different emission spectrum they all

have different emission lines

let's head to the drawing board and

figure out how to use those emission

lines

to tell what kinds of elements we find

in stars

so let's see if we can use a star's

emission spectrum

to identify which elements are in that

star

recall that an emission spectrum looks a

little bit like a rainbow

and that each of these colored lines is

an emission line

in this emission spectrum and keep in

mind that

a lot of times when you see an emission

spectrum it's shown in black and white

so rather than colored lines what we see

here are black lines

which simply represent those bright

bands of color we saw earlier

and by observing gas discharge tubes

like the ones we saw earlier

we know the emission spectra for pretty

much all known

elements here are just a few elements

along with their corresponding emission

spectra

that we'll use in some examples

for our first example let's try to use

an emission spectrum to identify which

elements we'll find in our

own sun here is a simple example of our

sun's emission spectrum

it's a mystery spectrum in that we don't

immediately know

which elements are in it

if we compare this mystery spectrum to

the spectra of elements that we

already know we can align them and find

out which elements are found

in the mystery spectrum carefully

examine

the emission spectrum for our sun

there are two elements hidden in our

sun's emission spectrum

see if you can identify which elements

those are

you might want to pause at these

intervals to give yourself as much time

as you want to figure out which elements

the mystery spectrum has

after careful analysis you might have

been able to identify

the emission lines for the element

hydrogen indicated here

in red but you'll also notice a variety

of lines that don't belong to hydrogen

those lines belong to the element helium

that means that our sun contains the

elements hydrogen

and helium and both of those elements

show up

in its emission spectrum

let's look at some more examples

this is the emission spectrum for star a

star a contains two elements can you

identify

which two elements are hidden in the

emission spectrum for star

a

after careful analysis you should have

been able to identify

the emission lines for hydrogen

indicated here in red and lithium

whose lines are indicated here in green

this means that star a contains the

elements hydrogen

and lithium by the way

the order in which you identify the

elements doesn't matter

however to be able to confidently say

that you spotted

a specific element in an emission

spectrum you technically have to be able

to identify

each and every individual emission line

that that

element produced if even one emission

line from that element

is missing that means that the element

is not present

in the star let's look at another

example

star b once again there are

two elements found in star b

and these ones are a little trickier

than the elements we found in the

previous example

look at the mystery spectrum for star b

and see if you can identify which

two elements are found in this star

after carefully analyzing the emission

spectrum for star b

the first element you probably

identified was

carbon indicated here in gold

these lines which don't belong to carbon

belong to

helium indicated here in blue

that means that star b contains both

carbon and

helium the next example once again

contains

two elements in star c

can you identify which two elements are

found in this star by using the emission

spectrum

if you looked carefully you should have

been able to identify the elements

oxygen indicated here in a pinkish hue

and helium indicated here in blue

that means that star c contains oxygen

and

helium

star d is our first example that

contains

three elements carefully examine the

emission spectrum and see if you can

pick out which

three elements are in star d

with any luck you should have been able

to identify

carbon's emission spectrum pretty

quickly indicated here in gold

then hopefully you identified the

emission lines for helium

indicated here in blue and finally

hidden among this forest of emission

lines are the three emission lines for

hydrogen

indicated here in red this means that

star d contains the elements

carbon helium and hydrogen

note that hydrogen and lithium because

their emission spectra are so

simple are often the most difficult to

find in a complex emission spectrum

example e is the emission spectrum for

yet another star that contains three

elements

see if you can identify which three

elements star e

contains

with a bit of luck and persistence you

might have been able to identify the

element

oxygen indicated here in pink

carbon indicated by gold

and helium indicated in blue

example f is another star that has three

elements in its spectra and it's

probably the trickiest one of all of the

examples

can you identify which three elements

are in the emission spectrum

for star f

after careful analysis if you were

patient and persistent

you should have been able to identify

the three elements in star f

these are nitrogen indicated here in

purple

helium indicated here in blue

and then hydrogen was hiding in the

background indicated here in red

we know lots about space thanks to

spectroscopy the study of emission

spectra that means that any element we

run into

we can find and study using this

technique

including hydrogen lithium nitrogen

chromium and much more using emission

spectra we have found out the

compositions of our planetary neighbors

such as jupiter

by studying the emission spectra of

jupiter's atmosphere we know it's made

mostly of

hydrogen and helium we've also

determined the elements in much more

distant neighbors such as the orion

nebula pictured here in

what are called narrowband wavelengths

in this image

the orange core is hydrogen the bluish

cloud is oxygen

and the red area surrounding that is

ionized sulfur

moving out still farther we can even

make interesting conclusions about the

compositions of other galaxies

such as the andromeda galaxy thanks to

spectroscopy the study of emission

spectra

we know that these dark bands are lanes

of dust

mostly carbon while these brighter fuzzy

areas

are rich in lighter elements such as

hydrogen gas

we've even used spectroscopy to estimate

the composition of the universe as a

whole

these thousand dots represent all the

atoms in the universe

of these most of them are hydrogen atoms

a significant chunk of them are helium

this little bit

is oxygen and the remaining fraction of

a percent

is all other elements combined

from this we know that nearly the entire

universe is made of hydrogen

and helium let's review the goal of this

video to make sure that you

met the goal after watching this video

you should be able to

use spectroscopy to determine the

elements that make up a star

if you can't do that go back and watch

the parts of the video that you didn't

understand

until next time remember you can learn

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