What is a galaxy?

• A large cloud of gas and dust
• A collection of millions of stars
• A single star
• A planet

Which type of galaxy is the Milky Way?

• Elliptical galaxy
• Spiral galaxy
• Irregular galaxy
• Lenticular galaxy

Which of the following is NOT a type of galaxy?

• Elliptical
• Circular
• Spiral
• Irregular

The Sun belongs to which galaxy?

• Andromeda Galaxy
• Triangulum Galaxy
• Milky Way Galaxy
• Whirlpool Galaxy

What is the origin of a star according to the Nebular Hypothesis?

• A planet
• A black hole
• A nebula
• A comet

What are the main components of a nebula?

• Oxygen and nitrogen
• Dust and gases such as hydrogen and helium
• Water and carbon
• Ice and iron

What force pulls the gases and dust together in a nebula to form a star?

• Magnetic force
• Gravitational force
• Nuclear force
• Electromagnetic force

What occurs when the temperature and pressure in a star's core become very high?

• Gravitational collapse
• A nuclear reaction
• Formation of a black hole
• Emission of X-rays

Which element is converted into helium during nuclear fusion in a star's core?

• Carbon
• Oxygen
• Hydrogen
• Nitrogen

What happens when a star runs out of hydrogen fuel?

• It expands and cools down
• It collapses and heats up
• It splits into two stars
• It explodes