The Sun's layers and the fusion that powers it
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
Use this
Star card cutaway of the Sun, not to scale:
On Ari's star card, the Sun's cutaway has four layers lettered A (center) to D (surface). Which layer is the core, where fusion happens?
- B, the next layer out from the center
- C, the layer below the surface
- D, the glowing surface, since it is hottest
- A, the center
Using the same lettered cutaway, which layer of the Sun is hottest, by Bo's reading?
Use the picture in question 1.
- C, the convection zone
- B, the radiative zone
- A, the core
- D, the photosphere, since it glows
Star card cutaway of the Sun, not to scale
A, the center; B, the next layer out; C, the layer below the surface, drawn with looping arrows; D, the visible surface.
Which layer of the same cutaway carries energy by hot plasma rising and cooler plasma sinking, by Kira's reading?
- C, the convection zone
- B, the radiative zone
- D, the photosphere
- A, the core
In the Sun's core, hydrogen nuclei join to make helium. What is this process called, by Jun's reading?
- Nuclear fusion
- Burning, like a campfire
- Melting
- Nuclear fission
Which statement describes nuclear fission, by Luz's reading?
- A heavy nucleus such as uranium splits into smaller ones
- Atoms change from a solid to a gas
- Light nuclei such as hydrogen join into helium
- Fuel combines with oxygen and burns
Why is the Sun not a giant fire, by Milo's reading?
- It runs on fission of hydrogen
- Burning needs oxygen; the Sun runs on fusion
- It gets its energy from Earth
- It is a fire; fire and fusion are the same
Star card cutaway of the Sun, not to scale, with an arrow from the center out to the surface. In which order does energy travel out from the Sun's center, by Noah's reading?
- Core → convection zone → radiative zone → photosphere
- Core → radiative zone → convection zone → photosphere
- Core → photosphere, straight out in 8 minutes
- Photosphere → convection zone → radiative zone → core
How does energy move through the Sun's radiative zone, by Pia's reading?
- As light, bouncing slowly outward
- As hot plasma rising and sinking
- As flames spreading outward
- Straight to the surface in about 8 minutes
About how long does light take to reach Earth after it leaves the Sun's photosphere, by Ren's reading?
- About 170,000 years
- About 8 minutes
- No time; it arrives instantly
- About 8 hours
“H-R diagram:” On the star card's H-R diagram, temperature runs from hot on the left to cool on the right. A star at the far left is what, compared with the Sun, by Tala's reading?
- Hotter than the Sun
- Cooler, since left means lower
- Cooler, since it is on the left
- The same temperature as the Sun