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Worksheets“Fusion Confusion: A Star’s Guide to Burning Bright”
Total questions: 25
Worksheet time: 13mins
Why are stars called the “element factories” of the universe?
They cook elements in their hot cores by fusion
They recycle planets into gas
They shine brighter than galaxies
They make atoms disappear
The collapse of a gas cloud into a protostar (baby star born) is mainly caused by:
Pressure from planets nearby
Gravity overpowering pressure
Supernova shockwaves only
Magnetic fields twisting the gas
What keeps a main-sequence star (like our sun) stable?
Gravity pulling in balanced by radiation pressure pushing out
Strong nuclear force pulling everything together
Magnetic attraction from galaxies
Rotation of the star
The Sun shines because:
Hydrogen fuses into helium in its core
Helium splits into hydrogen
Carbon is burned like coal
It reflects light from the Milky Way
Which condition is most critical for starting nuclear fusion?
Large amounts of oxygen
Freezing cold vacuum
Planetary magnetic fields
Very high core temperature and pressure
Why can’t stars fuse elements heavier than iron in their cores?
Iron nuclei are too heavy to move
Fusion beyond iron absorbs energy instead of releasing it
Iron is unstable in stars
Stars cool down iron immediately
Which process forms gold and uranium in the universe?
Hydrogen burning in stars
Helium fusion in red giants (old age stars)
Supernova explosions and neutron star mergers
White dwarf cooling
A protostar is like a baby star 👶 because:
It is already fusing hydrogen steadily
It is just collapsing, warming up, and not stable yet
It has retired from fusion
It has exploded into a supernova (dramatic like high school kids!)
Which star stage is like an adult with a steady job?
Protostar
Main sequence — burning hydrogen to helium reliably
Red giant — bloated old age
White dwarf — retired and cooling
The single property that decides a star’s life cycle is:
Its hairstyle (brightness) — looks flashy, but doesn’t change how long it lives ✨
Its mood swings (temperature) — hot or cool, but not the real boss 🌡️
Its weight (mass) — heavier stars live fast and die young, lighter ones live long 🏋️♂️
. Its shoe size (radius) — big feet don’t decide destiny 👟
The Sun today is in which life stage?
Protostar (baby star born 👶) — but our Sun stopped crying photons billions of years ago.
Main sequence (adult star 🧑) — steady job: burning hydrogen into helium every day.
Red giant (old star 👴) — that’s its future self, puffed up and cranky.
White dwarf (retired ⚰️) — still glowing, but our Sun isn’t retired yet!
Compared to the Sun, a more massive star will:
Live longer — it has more snacks 🍔
Live shorter — like a sports car burning fuel at full speed 🚗💨
Live the same no matter what ⏳. Like a Clone of Sun.
Never die, immortal like a superhero 🦸
A red giant is best described as:
A star in its teenage years, throwing tantrums 😎🔥
An old star that has swollen up, burning helium and heavier stuff 👴🎈
A star that just retired and is glowing faintly 🪑
A star at the gym, getting denser and stronger 💪
A supernova can be thought of as:
A star quietly retiring on a beach chair 🏖️
A dramatic midlife crisis where the star goes out with a bang 💥
A baby star throwing a tantrum in the crib 👶
A planet trying to get attention 🌍✨
A white dwarf is like:
A retired professor still glowing faintly with wisdom 🎓
A teenager blasting music and showing off flares 🔥🎶
A young adult steadily paying hydrogen bills 💡
A black hole swallowing everything in sight 🕳️
White dwarfs are mainly made of:
Hydrogen gas
Carbon and oxygen
Gold
Helium plasma
Why is it difficult to build a working fusion reactor on Earth?
Hydrogen is rare on Earth
Stars don’t want competition 😜
It is hard to maintain very high temperatures, density, and confinement time for plasma
Gravity is too strong on Earth
In a fusion reactor, “plasma” refers to:
A beam of photons
Solid metallic hydrogen
A liquid hydrogen fuel
Super-heated soup of free ions and electrons
Which of the following improves the chance of nuclear fusion?
Keeping the plasma in a tight hug for longer (longer confinement time) 🤗🔥
Cooling it down with an ice pack (lower temperature) 🧊
Making the plasma super thin so particles never meet (shorter density) 🌫️
Freezing the plasma into ice cubes (solid fusion snacks) 🍦
Why is space cold even though stars are everywhere?
Space runs a giant cosmic air-conditioner ❄️🌀
Stars only bother to shine in daytime 🌞
Space is mostly empty, so there’s nothing to soak up the heat 🥶
Stars are just tiny campfires too far away 🔥🏕️
The last element a massive star can build in its core is:
Uranium — way too fancy for a star’s budget 💰
Gold — pretty jewellery, but only made in supernova chaos 💍💥
Carbon — baby building block, but not the endgame 🌱
Iron — the stubborn grandparent that refuses to fuse any further 🧓🔩
In the Sun, the plasma is held together mainly by:
Electric currents — like a tangled mess of wires 🔌
Gravity — the giant cosmic hug keeping everything squished 🤗
Earth’s magnetism — sorry Earth, you’re way too weak 🌍
The cosmic microwave background — leftover baby blanket from the Big Bang 🍼🌌
Which star type is matched correctly with its fusion process?
Main sequence — hydrogen fusing into helium, steady adult job 💼
Red giant — casually turning iron into uranium on weekends 🧪
White dwarf — still fusing helium even though it’s retired 🛌
Neutron star — secretly burning hydrogen (as if!) 💪
Which factor is not part of the Lawson criterion for fusion?
Plasma temperature — gotta be sizzling hot 🔥
Plasma density — the more particles, the merrier 💃
Confinement time — keep them locked in long enough ⏳
Star’s distance from Earth — sorry, IB doesn’t care how far it is 🚀😂
Why does fusion of light elements (like H into He) release energy?
Because the nuclei are bored and want to party 🎉
Because Einstein personally adds E=mc^2 every time 🔬
Because the binding energy per nucleon increases, and the difference comes out as energy 💡
Because helium is shinier than hydrogen ✨
