What is the systematic process of asking questions about the observable world by gathering and studying information called?

• Hypothesis

• Science

• Experimentation

• Observation

What does the universe's observable mass mostly consist of?

• Oxygen atoms

• Carbon atoms

• Hydrogen atoms

• Nitrogen atoms

What is the process called when gravity pulls the heaviest materials to the center of the Earth as it forms?

• Stratification

• Erosion

• Sedimentation

• Crystallization

Approximately how many years ago did Earth's first solid surface form?

• 3.5 billion years ago

• 4.6 billion years ago

• 2.5 billion years ago

• 5.6 billion years ago

Where did life probably originate shortly after Earth formed?

• In the atmosphere

• In the ocean

• On land

• In space

What appears to be present in other places in our solar system besides Earth?

• Solid land

• Liquid water

• Atmosphere

• Vegetation

What percentage of Earth's surface is covered by ocean?

• 50%

• 70%

• 97%

• 85%

What is the average depth of the ocean according to Table 1.1?

• 3,682 meters

• 5,000 meters

• 10,994 meters

• 2,000 meters

What is the average temperature of the ocean?

• 10°C

• 3.9°C

• 15°C

• 7°C

What is the total mass of the ocean as mentioned in Table 1.1?

• 1.41 billion billion tons

• 2 billion billion tons

• 1 billion billion tons

• 1.5 billion billion tons