SHS Physical Science Q1 Ep2: Formation of Heavy Elements (Part 2)

Summary

This educational video script explores the formation of elements in stars for grade 12 physical science students. It explains the processes of nuclear fusion and neutron capture, detailing how lighter elements like hydrogen fuse to form heavier ones like helium, and how elements heavier than iron are produced. The script covers the life cycle of stars, from stellar nebulae to supernovae, and introduces the CNO cycle and the triple alpha process. It also touches on the significance of these celestial events for understanding the origin of elements essential to life on Earth.

Takeaways

• 🌟 Stars are born from huge gas clouds called stellar nebulae, where gravity pulls gas and dust particles together, increasing temperature and pressure until hydrogen atoms begin to fuse, releasing energy and light.
• 🔥 The core of a star is where nuclear fusion occurs, primarily the fusion of hydrogen atoms into helium, which releases a significant amount of energy that counteracts the star's gravitational force.
• ☀️ Our Sun, a main sequence star, will continue fusing hydrogen for approximately 5 billion more years, after which it will run out of hydrogen and start to collapse, leading to the formation of a red giant.
• 🌌 The fate of a star depends on its size; average-sized stars become red giants, while more massive stars become supergiants, with the latter fusing elements heavier than carbon up to iron.
• 💥 Supernovae are massive explosions that occur when a star can no longer withstand its own gravity, leading to a core collapse and an explosion that disperses newly formed elements throughout space.
• 🌑 Elements heavier than iron are primarily formed during supernovae or through the collision of two neutron stars, a process that releases enough energy to facilitate their creation.
• 🔬 The CNO cycle, or carbon-nitrogen-oxygen cycle, is a process in which hydrogen atoms fuse to form helium in larger stars, involving carbon, nitrogen, and oxygen as catalysts.
• 🔬 The triple alpha process is the fusion of three helium nuclei to form carbon, a critical step in the formation of heavier elements within stars.
• 🔬 The alpha ladder process involves the successive fusion of helium nuclei with heavier elements to form even heavier elements, such as oxygen, neon, magnesium, and silicon.
• 🌌 Neutron capture is a process where a seed nucleus, like iron, absorbs neutrons, which can later transform into protons, thus creating elements with higher atomic numbers than iron.

Q & A

What is the primary source of energy for living things on Earth?

The primary source of energy for living things on Earth is the Sun, which provides energy through sunlight that plants use to make carbohydrates.

How are stars born?

Stars are born inside a huge gas cloud called the stellar nebula, which is composed mostly of hydrogen and helium. The gas and dust particles come together due to gravity, forming clumps that eventually lead to nuclear fusion and the birth of a star.

What is the process called when hydrogen atoms fuse to form helium in a star's core?

The process is called nuclear fusion, specifically the proton-proton chain reaction in medium-sized stars like the Sun, and the CNO cycle in high-mass stars.

What happens to a star once it runs out of hydrogen in its core?

Once a star runs out of hydrogen in its core, it can no longer hold against gravity, leading to a collapse of its inner layer. The core shrinks, and as the star collapses, the temperature and pressure at the core increase.

What are the two possible outcomes for a star when it runs out of fuel?

An average-sized star becomes a red giant, while a massive star becomes a supergiant. Red giants are capable of fusing helium atoms to produce carbon and oxygen, and supergiant stars can fuse elements heavier than carbon up until iron.

What is the triple alpha process and why is it significant?

The triple alpha process is the fusion of three helium nuclei (alpha particles) to form a carbon nucleus. It is significant because it is the primary method by which heavier elements than helium are formed in stars.

What is the difference between the s process and the r process in neutron capture?

The s process (slow neutron capture process) occurs in less energetic environments and takes place over thousands of years inside dying stars. The r process (rapid neutron capture process) occurs in supernovae or neutron star mergers, where a large number of neutrons are captured in about one to two seconds.

How do elements heavier than iron form in stars?

Elements heavier than iron form through the process of neutron capture, where a seed nucleus is bombarded with neutrons, which eventually turn into protons, leading to the formation of heavier elements.

What is the role of supernovae in the formation of heavy elements?

Supernovae play a crucial role in the formation of heavy elements by providing the necessary high-energy environment for the rapid neutron capture process (r process), which is responsible for creating elements heavier than iron.

Why are the elements found in our bodies, like oxygen, calcium, and iron, linked to stars?

These elements are linked to stars because they are primarily formed inside stars through various nuclear fusion and neutron capture processes. Supernovae and other stellar explosions then disperse these elements into space, where they can become part of new stars and planetary systems, including our own solar system.

Outlines

00:00

🌟 Introduction to Stellar Nucleosynthesis

This paragraph introduces the episode's focus on physical science for grade 12 students, inviting all interested learners to join. The host, Teacher Iman, encourages participants to take notes as they explore how heavier elements are formed inside stars, building upon the previous episode's discussion on light element formation during the Big Bang. The episode aims to educate in a fun and accessible manner, starting with the fundamental question of how stars, which are crucial for life on Earth, produce energy.

05:00

🌌 The Life Cycle of Stars and Energy Production

The second paragraph delves into the life cycle of stars, explaining how they are born from stellar nebulae and grow through the process of nuclear fusion in their cores. It discusses the role of gravity in star formation and the critical balance between the outward pressure from nuclear fusion and the inward pull of gravity. The paragraph also introduces the concept of different star sizes leading to different fates, such as red giants or supergiants, and hints at the processes that create heavier elements within stars.

10:00

🔥 Advanced Nuclear Fusion and Element Formation

Paragraph three continues the exploration of stellar nucleosynthesis, focusing on the processes that occur in the cores of red giants and supergiants. It explains the triple alpha process, where three helium nuclei combine to form carbon, and the alpha ladder process, which involves the fusion of helium with heavier elements. The paragraph also touches on the formation of elements heavier than iron through neutron capture, setting the stage for a deeper discussion of these processes.

15:02

⚛️ Neutron Capture and Heavy Element Synthesis

The fourth paragraph provides a detailed explanation of the neutron capture process, which is essential for the formation of elements heavier than iron. It distinguishes between the s-process and r-process, describing the conditions under which these processes occur and how they contribute to the creation of heavy elements. The paragraph emphasizes the importance of understanding these processes for appreciating the origins of the elements that make up our world.

20:04

📚 Review and Encouragement for Learning

In the final paragraph, the episode concludes with a series of review questions to test the audience's understanding of the concepts discussed. It also reflects on the importance of learning these scientific processes, even for those not pursuing scientific careers, as they train the mind in memory, connection-making, and interpretation of processes. The host, Teacher Iman, encourages continuous learning and teases the next episode's topic on laboratory synthesis of elements.

Keywords

💡Nuclear Fusion

Nuclear fusion is a process where atomic nuclei come together to form a new, more massive nucleus, releasing energy in the process. In the context of the video, nuclear fusion is central to understanding how stars generate energy. The script explains that hydrogen atoms fuse to form helium, releasing a lot of energy and light, which is the fundamental process that powers stars. This process is crucial for the life cycle of stars and the creation of heavier elements.

💡Stellar Nebula

A stellar nebula is a vast cloud of gas and dust in space, primarily composed of hydrogen and helium, along with other elements. In the video script, the stellar nebula is described as the birthplace of stars, where gravity causes the gas and dust to coalesce, eventually leading to the conditions necessary for nuclear fusion to begin and a star to be born.

💡Red Giant

A red giant is a late stage in the life cycle of a medium-sized star, where the star expands significantly in size after exhausting the hydrogen fuel at its core. The video explains that once a star runs out of hydrogen, it can no longer counteract gravity with the outward pressure from nuclear fusion, leading to a collapse of the core and an expansion of the outer layers, turning the star into a red giant. This phase is significant for the star's evolution and its eventual fate.

💡Supernova

A supernova is a powerful and luminous explosion that occurs at the end of a massive star's life. The script describes a supernova as an event where the outer layers of a star are ejected, and the core is exposed, resulting in a release of an immense amount of energy that can outshine an entire galaxy. Supernovae play a critical role in the universe by spreading heavy elements formed within the star into space, contributing to the formation of new stars and planets.

💡Neutron Star

A neutron star is the collapsed core of a massive star that has undergone a supernova explosion. The video script mentions neutron stars in the context of the rapid neutron capture process, which occurs in supernovae or neutron star mergers. Neutron stars are incredibly dense and are composed almost entirely of neutrons, making them fascinating objects for studying the properties of matter under extreme conditions.

💡CNO Cycle

The CNO cycle, also known as the carbon-nitrogen-oxygen cycle, is a set of nuclear reactions that occur in stars more massive than the Sun. The video script explains that this cycle is an alternative pathway for hydrogen fusion in such stars, involving the isotopes of carbon, nitrogen, and oxygen as catalysts. The CNO cycle is significant for understanding the energy production in different types of stars and contributes to the overall nucleosynthesis within them.

💡Triple Alpha Process

The triple alpha process is a nuclear reaction in which three helium nuclei (alpha particles) combine to form a carbon nucleus. This process is highlighted in the video as a critical step in the formation of heavier elements within stars. The script notes that this process releases energy and is essential for the production of carbon, which is a building block for the formation of more complex elements.

💡Alpha Ladder Process

The alpha ladder process is a series of nuclear reactions where helium nuclei (alpha particles) are added to heavier elements, creating even heavier elements. The video script describes this process as a continuation of the fusion reactions that start with the triple alpha process, allowing for the formation of elements like oxygen, neon, magnesium, and beyond. This process is key to understanding the synthesis of elements beyond helium in stars.

💡Neutron Capture

Neutron capture is a nuclear process where an atomic nucleus absorbs a neutron, which may then decay into a proton, effectively increasing the atomic number of the nucleus and thus creating a heavier element. The video script explains two types of neutron capture processes: the rapid (r-process) and slow (s-process), both of which are essential for the formation of elements heavier than iron. Neutron capture is a significant process in the universe's elemental composition.

💡Stellar Nucleosynthesis

Stellar nucleosynthesis refers to the process of element formation within stars through nuclear reactions. The video script discusses how elements heavier than helium are formed inside stars through various fusion processes and neutron capture. This concept is central to understanding the origin of elements and the life cycle of stars, as it explains how stars act as cosmic factories for creating the elements necessary for life as we know it.

Highlights

Introduction to the episode focusing on physical science for grade 12 students.

Exploration of how heavier elements are formed inside stars, continuing from the previous episode on light element formation during the Big Bang.

Discussion on the energy requirements for living organisms and the role of the sun as an energy source.

Explanation of how plants utilize sunlight for energy through the process of photosynthesis.

Description of the life cycle of stars, from birth in stellar nebulae to the fusion of elements at their cores.

Detailed account of nuclear fusion within a star's core, where hydrogen fuses to form helium.

The concept of a star's outward pressure balancing its inward gravitational force, preventing collapse.

Forecast of the sun's future, fusing hydrogen for another 5 billion years before running out.

The process of a star's transformation into a red giant or supergiant once it depletes its hydrogen.

The role of red giants and supergiants in fusing helium to form heavier elements like carbon and oxygen.

The dramatic end of a red supergiant's life, exploding as a supernova and spreading newly formed elements.

The aftermath of a supernova, leaving behind either a neutron star or a black hole, and the formation of elements heavier than iron.

Introduction to the CNO cycle as an alternative process for fusing hydrogen to helium in larger stars.

Explanation of the triple alpha process, where three helium nuclei combine to form carbon.

Description of the alpha ladder process, which involves the fusion of helium with progressively heavier elements.

Introduction to neutron capture as a method for forming elements heavier than iron.

Differentiation between the s-process and r-process of neutron capture, detailing their environments and timescales.

The educational value of understanding stellar nucleosynthesis, even for those not pursuing scientific careers.

Encouragement to join the next episode, which will discuss element synthesis in laboratories.

Transcripts

[Music]

me

good day everyone this episode is for

grade 12 students who are studying

physical science

but of course everyone who is willing

and interested to learn

is welcome to join us make sure that you

have a pen and paper with you so you can

write the things

that you will learn from this episode i

am teacher iman and i welcome you to the

second episode of science cuellar tv

where you can learn science concepts in

fun and easy way

in our previous episode we learned how

the light elements were made

during the big bang nucleosynthesis and

how hydrogen atoms fuse to form helium

inside the stars

in this episode we will discover how

heavier elements are formed

inside the stars and let's watch this

documentary

about the stars and learn more about

what goes on inside these hot balls of

plasma

all living things require energy not

only to engage in activities like

walking running or swimming but also to

survive

without energy we will not be able to do

simple things like

eating talking or even breathing

our body needs energy to keep going our

heart needs energy to pump blood

throughout the body

and our lungs need energy to breathe

thanks to the sun

we can get the energy we need to do

these things

i am correspondent sunny and this is my

report

plants use sunlight to make

carbohydrates

which becomes our main source of energy

and where does the sunlight come from of

course

from the nearest star in our planet the

sun

[Music]

our sun is just one of the billions of

stars in the milky way galaxy

and one of the billions of trillions of

stars

in the universe they come in different

sizes and colors

all of them release energy each of them

fuse elements at the core to form new

ones

how are the stars born where do the

light and energy they release come from

do stars explode what happens to them

when they do

we have asked the manila street

astronomers to help us find answers to

these questions

one of the more common questions asked

about stars

is how are the stars born well

a star is born inside a huge gas cloud

made up mostly of hydrogen

helium dust particles and called the

stellar nebula

these gas and dust particles begin to

come together due to the force of

gravity

and these clumps merge together to form

bigger clumps

the force of gravity increases the

kinetic energy of the dust and

gas particles this increases the

temperature

of the nebula temperature and pressure

becomes so great

that the hydrogen atom starts to fuse

this fusion of hydrogen atoms release a

lot of energy

and light giving birth to a star

stars are able to brighten the night sky

because of the energy they release

the star's core is where most of its

energy is produced

hydrogen atoms fuse together to form

helium

which releases a lot of energy in the

process

this process is called nuclear fusion

the powerhouse of a star is the core the

energy released from the nuclear fusion

provides the outward pressure

that counters the inward gravitational

force of a star

without this outward pressure the star

will collapse

our sun will continue to fuse hydrogen

for the next 5 billion years

what happens after that what happens

when it runs out of hydrogen

in its core

so once a star runs out of hydrogen it

can no longer hold against gravity

it in its inner layer will start to

collapse due to gravity

and the core shrinks so as the star

collapses

the temperature and the pressure at the

core increases

eventually the core becomes hot enough

for helium atoms to fuse and form new

or heavier elements at this stage the

star expands

bigger and forms either a red giant or a

supergiant

the fate of a star depends on its size

an average sized star will become a red

giant

while a massive size star will become a

super giant star

red giants are capable of fusing helium

atoms to produce

carbon and oxygen supergiant stars can

fuse

elements heavier than carbon up until

iron

when a red giant runs out of helium to

fuse

the outer layers are ejected eventually

its core will be exposed though dead

the core will remain hot for billions of

years

it is called a white dwarf

red supergiants do not die as quietly

when it dies it collapses and then it

explodes

the explosion is so big that it releases

a huge amount

of energy for days and even for weeks

it can outshine the whole galaxy

now a supernova happens when a

supergiant can no longer

release energy from fusion the

outward pressure reduces from its core

eventually decreases

and until it can no longer withstand

the inner force of the gravity this

causes the star to collapse to a smaller

and denser core

it produces an enormous shockwave that

causes the explosion

the explosion also spreads the newly

formed elements throughout

outer space they can

become building blocks for future

planets and other stars

a supernova will then leave behind

either a neutron star

or a black hole the energy released by

the supernova

makes it possible for the elements

heavier than iron to be formed

aside from supernova elements heavier

than iron can also be formed from

collision

of two neutron stars it is truly

beautiful to behold how stars brighten

the night sky

but it is more amazing to realize that

the oxygen that we breathe

the calcium in our bones the iron in our

blood

were made inside these stars as to the

process of how these elements were made

i'll let professor proton teach you that

hello everyone and welcome to my

classroom i

am professor proton and i will be

discussing a different process by which

heavier elements are made on the

previous episode

my friend professor atom taught you how

helium is formed

through the proton-proton chain reaction

that process is more dominant in

medium-sized star

just like the sun but for bigger stars

the more dominant process in fusing

hydrogen

to form helium is called the cno cycle

or

the carbon nitrogen oxygen cycle

the process starts when a hydrogen atom

or a proton collides and combines

with carbon-12 atom

if you look at the periodic table of

elements you will see that carbon has an

atomic number of 6.

this means that it has 6 protons why

then do we call it carbon-12

the number 12 here represents the mass

number or the total number of protons

and neutrons

this means that carbon-12 has six

protons

and six neutrons

when hydrogen atom hits carbon 12 one

proton is added to the nucleus

now it has seven protons

and six neutrons

we learned in our last episode that the

identity of an element depends on how

many protons it has

now that the number of protons in the

nucleus has changed

its identity has also changed as you can

see

it has turned into nitrogen 13. instead

of 6

the nucleus now has 7 protons this

nitrogen 13 is not stable

it will eventually turn into carbon 13.

how did that happen one of the protons

in nitrogen 13

turns into a neutron this changes the

total number of protons

into six and the total number of

neutrons into seven

six protons

and seven neutrons

later another hydrogen atom will hit

carbon 13

the total number of protons will change

again as you can see from carbon 13

the nucleus turned into nitrogen 14

because instead of having 6 protons and

7 neutrons

we now have seven protons

and seven neutrons

then another hydrogen atom collides and

combines with the nucleus

this results to the formation of oxygen

15.

the change was caused by the addition of

proton in the nucleus

now the nucleus has eight protons

and seven neutrons

what we have left is another unstable

nucleus

one of the protons in oxygen 15 turns

into a neutron

since the number of protons changes the

identity of the element changes

it will become nitrogen 15 atom

and nitrogen 15 has seven protons and

eight neutrons

seven protons

and eight neutrons

lastly the fourth hydrogen atom hits

nitrogen 15.

now we have a total of eight protons and

eight neutrons

however two protons and two neutrons are

released

that is helium now what is left is

another carbon-12 atom that has six

protons and six neutrons if another

hydrogen atom hits carbon-12

then another cycle occurs as you can see

four hydrogen atoms were used in the

process

one two three

four and this is how helium is formed

through the cno cycle thank you

professor proton

the cno cycle will only work as long as

there is hydrogen to keep the cycle

going

earlier we learned what happens when the

stars no longer fuse hydrogen

at their core medium-sized stars turn

into red giants

and massive stars turn into supergiant

inside these dinostars elements heavier

than helium are being fused

my friend professor electron will show

you what happens

inside their cores hi this is professor

elektron and i'm here to show you the

processes

at which elements heavier than helium

are made

but first we need to go inside the core

of a dying star when a star turns into a

red giant

the core is filled with helium atoms

that are fusing together to form new

elements

three nuclei of helium colliding combine

together

to form carbon through the process

called triple alpha process

the process starts with two helium

nuclei colliding and combining together

to form beryllium this beryllium is

highly unstable and it could decay back

into a smaller atom

however if another helium atom collides

and combines with it before it decays

carbon is formed

this process releases energy and because

of that

some carbon nuclei fuse with additional

helium

and forms oxygen notice that three

helium nuclei

refuse to form carbon helium nuclei is

also known as alpha particle that is why

the process is called

triple alpha process now let's take a

look at how

the alpha ladder process occurs

another type of nuclear fusion process

that combines helium

to form heavier elements is the alpha

ladder process

the basic concept is the same atomic

nuclei collide and combine to form

heavier ones

and since this is an alpha process

helium nuclei

are always involved in the said reaction

for example

carbon combines with helium to form

oxygen and then oxygen fuses with helium

to form neon then neon combines with

another helium to form

magnesium and so on and so forth

triple alpha process and alpha ladder

process

fuse helium nuclei heavier elements can

also be formed through diffusion of

other heavy elements

for example two carbon nuclei can fuse

to form

magnesium this is called carbon burning

another example is when two

oxygen nuclei combines to form

silicon this is oxygen burning

[Music]

now if we want to understand how

elements heavier than iron are formed

we'd have to talk about a different

process and that process

is neutron capture it is very difficult

to make heavy elements by fusing them

together

it requires a very large amount of

energy

this is because the heavier the element

gets the more protons it has and when

you bring protons closer to one another

they repel each other because they have

the same charge

that is where neutrons come into play

unlike protons and electrons neutrons

have no charge

it is easier for them to approach an

atom and get

absorbed by it that's the basic concept

of neutron capture you have a seed

nucleus like carbon or iron and then you

bombard it with neutrons and they get

absorbed in the nucleus

this will increase the mass of the

nucleus but you have to remember

it will not change its identity if the

seed nucleus is iron the addition of

more

neutrons does not change its identity

however

some of these neutrons will eventually

turn into protons and when that happens

you'll have elements that have an atomic

number

higher than iron

there are two types of neutron capture

the s

process and the r process the s stands

for slow and v

r stands for rapid slow and rapid refers

to how fast the neutron bombardment

occurs

let's discuss the rapid neutron capture

process

in this process the seed is bombarded

with

huge number of neutrons in about one to

two second time scale

for this to occur there must be a lot of

neutrons and there must be

a lot of energy scientists believe that

the r

process occurs in supernovae or star

explosions

and in neutron star mergers or the

collision of two neutron stars

as shown earlier the neutrons that were

captured by the seed nucleus

will eventually turn into protons

the slow neutron capture process occurs

in less energetic environment than

supernova

and neutron star mergers it takes place

inside the dying stars

unlike vr process the bombardment of

seed nucleus with neutrons

takes a long time it can take thousands

of years

how does this process work we know from

the earlier discussion that for

neutron capture to occur the environment

must be

rich in neutrons apparently the alpha

processes produce a lot of free neutrons

these neutrons are captured by the seed

nucleus but it takes a longer time to

happen

that's how the heavier elements are made

through nuclear fusion

and neutron capture oh

i have to go i still have to do some

combination of protons and neutrons

see you wow did you have fun learning

about the processes that formed the

elements

i'm sure you did let's review them

we have already answered one of the most

interesting questions in science

how were the elements formed all

elements

originally formed from hydrogen which

was formed during the big bang

nucleosynthesis

a few moments after the big bang protons

and neutrons collided and combined to

form helium

and some lithium and beryllium elements

also formed inside the stars in a

process called

stellar nucleosynthesis hydrogen atoms

fuse to form helium through the

proton-proton chain reaction

and cno cycle proton-proton chain

reaction is dominant in medium-sized

stars like the sun

and cno cycle is dominant in high mass

stars

elements heavier than helium are formed

from further collision and combination

when three alpha particles or three

helium nuclei collide and combine to

form carbon

the process is called triple alpha

process

helium nuclei can further fuse with

elements like oxygen

neon magnesium silicon etc in a process

called alpha ladder process

elements heavier than iron are formed

through the process of neutron capture

where a seed nucleus is bombarded with

neutrons which makes the elements

unstable

a fraction of the neutrons will then

turn into protons

to make a more stable element there are

two types of neutron capture process

the r process and the s process the r

processor rapid neutron capture process

occurs in supernovae

and neutron star mergers the s process

or slow

nutrient capture process occurs in dying

stars

now it's time to check how much you

understood from the episode

all you have to do is to choose the

letter of the best answer

let's start with an easy question

question number one

what is the explosion of the stars

called

a supernova b

black hole c neutron star

or d big bang

[Music]

the correct answer is a supernova

question number two which of the

following gases

are the major components of a main

sequence star

a carbon and oxygen

b helium and carbon

c hydrogen and carbon or

d hydrogen and helium

[Music]

the answer is d hydrogen and

helium question number three

what object is formed from gas and dust

particles

which are pulled together by gravity and

no nuclear fusion has happened yet

a nebula b

main sequence star c

red giant or d red

supergiant

[Music]

the correct answer is a nebula

question number four which of the

following

refers to the process at which three

helium nuclei

are converted into carbon

a cno cycle b

neutron capture c

supernova nucleosynthesis or d

triple alpha process

if you answer d then you are correct

triple

alpha process

number five which of the following

processes

takes place in supernovae and neutron

star mergers

a cno cycle b

rapid process neutron capture

c slow process neutron capture

or d triple alpha process

the answer is b rapid process neutron

capture

how did you do did you find the

questions easy to answer

i hope you did before we end this

episode i'd like to share something that

i hope will encourage you

you might be thinking why it is

important for you to learn the processes

we discussed in this episode

how are you going to use them in your

future job or endeavors

it is highly likely that you will not

unless you work as a scientist or

teacher like me

then why are we teaching this no matter

what type of job you will have in the

future

you will be required to learn processes

and how things are done

by learning about these things you are

training your mind to be

better at remembering processes improve

your ability to see the connections

between step one and step two

and easily interpret illustrations that

show

processes like illustration that shows

the process of cno cycle

or a very useful illustration that shows

how cpr is done

and that's it for this episode of

sciencequella tv on our next topic we

will talk about how the elements are

synthesized inside a laboratory

don't forget to tune in on our next

episode because

learning science with teacher iman is

fun

[Music]

you