Early Earth & Geo Time Review

Q: What gases entered Earth’s early atmosphere due to the outgassing of volcanoes?

• Oxygen, Hydrogen, and Helium

• Water vapor, carbon dioxide and nitrogen

• Carbon dioxide, oxygen, and hydrogen

• Nitrogen, oxygen, and water vapor

Q: Why was an oxygen rich atmosphere important for the evolution of life?

Choose all that apply

• All life needs oxygen to survive.

• Complex life needed oxygen to evolve.

• Ozone molecules (made of 3 oxygen atoms) filter out UV radiation from the sun which would harm evolving life.

• All answers are true

Q: Where did the water that ended up in Earth’s oceans originate from?

• Cyanobacteria undergoing photosynthesis

• Volcanic outgassing.

• Asteroid, meteorite, and other space object bombardment.

• All answers are true

 What do scientists believe prevented life from existing on Earth before 3.9 bya?

• Earth was too cold before 3.9bya.

• There wasn’t enough iron oxides on Earth before 3.9bya.

• Earth was being bombarded by asteroids and meteorites.

• All answers are true

Atmosphere #1, Which elements/molecules were present?

• Hydrogen

• helium

• carbon dioxide

• water

According to scientists, both Earth and moon are...

• About 1.6 Billion Years Old
• About 4.6 Billion Years Old
• About 9.6 Billion Years Old
• About 14 Billion Years Old

After water vapor condensed to form rain and then gradually accumulated, which of the following was formed?

• Earth's First Atmosphere
• Earth's Second Atmosphere
• Earth's Oceans
• Earth's Continents

Which of the following is NOT an important part of Earth's early second atmosphere?

• Helium
• Nitrogen

• Water Vapor
• Carbon Dioxide

The earliest form of life known on Earth was...

• Leafy Plants
• Animals

• Fossils
• Single-Celled Organisms

According to scientists, Earth began as a ball of dust, rock, and __________.

• Ice
• liquid water