Stars and Galaxies

1. What primary element makes up the giant gas clouds that eventually form stars?

• A. Oxygen
• B. Hydrogen
• C. Carbon
• D. Iron

2. What is the name of the process that allows a star to produce energy by fusing atoms together?

• A. Gravity pulling
• B. Supernova explosion
• C. Nuclear fusion
• D. Atmospheric heating

3. Which of these is NOT one of the three main shapes of galaxies mentioned?

• A. Spiral
• B. Elliptical
• C. Irregular
• D. Square

4. What do we call the state of matter of a star, where gas is so hot that electrons are stripped away?

• A. Plasma
• B. Solid
• C. Liquid
• D. Ice

1. Why does a star remain a stable, glowing sphere for millions of years instead of collapsing?

• A. The star is solid and cannot be crushed.
• B. Gravity pushes outward while fusion pulls inward.
• C. The energy from nuclear fusion pushes outward, balancing gravity pulling inward.
• D. The vacuum of space prevents the star from shrinking.

2. If you are looking at a distant galaxy through a telescope, why is it like looking into a time machine?

• A. Because light takes time to travel across space to reach our eyes.
• B. Because galaxies only exist in the past.
• C. Because the telescope slows down time for the observer.
• D. Because galaxies are moving toward us at high speeds.

3. What role does a supernova play in the cycle of the universe?

• A. It destroys all matter so nothing new can be formed.
• B. It creates heavy elements and scatters them to help form new planets and life.
• C. It marks the transition of a star from a solid to a liquid.
• D. It slows down the rotation of the entire galaxy.

4. How do scientists know that dark matter exists?

• A. They can identify it by its bright, glowing color.
• B. It is the only material that makes up spiral arms.
• C. Galaxy edges rotate faster than visible matter should allow, implying extra invisible mass.
• D. They have captured dark matter samples using deep-space probes.