Formation of the Solar System

What was the solar nebula?

• A type of star that exploded

• A giant cloud of gas and dust that formed the solar system

• A planet that existed before Earth

• A theory about how the Moon was formed

Why was nuclear fusion important in the early solar system?

• It helped cool down the planets.

• It created the Sun and provided energy for the solar system.

• It formed the first oceans on Earth.

• It caused the planets to collide.

How did Earth’s atmosphere change over time?

• It became thicker and contained more oxygen.

• It was always the same since Earth formed.

• It started with no gases and became filled with oxygen.

• It changed from being mostly nitrogen to being mostly carbon dioxide.

What was a significant event that led to the formation of the Moon?

• A comet collided with Earth.

• An asteroid the size of Mars hit Earth.

• The Sun exploded.

• Earth split into two pieces.

Which gases were present in Earth’s first atmosphere?

• Oxygen and helium

• Nitrogen, carbon dioxide, hydrogen, and water vapor

• Methane and oxygen

• Carbon dioxide and ozone

How did the early oceans form?

• They were created by the Sun’s heat.

• Water vapor condensed and fell as rain over millions of years.

• They were formed by ice melting from comets.

• They were always present since Earth formed.

What are the three layers of Earth and how do they differ in density?

• Core, mantle, crust; the core is the least dense.

• Crust, mantle, core; the crust is the most dense.

• Mantle, core, crust; the mantle is the most dense.

• Crust, core, mantle; the core is the most dense.

If Earth had been much cooler when it first formed, what might have happened to its interior?

• It would have melted completely.

• It would have formed a solid surface without layers.

• It would have developed layers but with less differentiation.

• It would have created more volcanoes.

What role did volcanoes play in the formation of Earth’s early atmosphere?

• They cooled the planet down.

• They released gases that contributed to the atmosphere.

• They created the oceans.

• They formed the crust.

How does the current atmosphere differ from the early atmosphere of Earth?

• The current atmosphere has more carbon dioxide.

• The early atmosphere had more oxygen than today.

• The current atmosphere has much more oxygen.

• The early atmosphere was made entirely of water vapor.