Orogeny and Early Earth

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 second atmosphere?

• Helium
• Oxygen
• Water Vapor
• Carbon Dioxide

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

• Leafy Plants
• Bacteria
• Fossils
• Single-Celled Organisms

Scientists believe that __________ and the moon are about the same age.

• Earth
• Comet

According to scientists, over billions of years, Earth's ________ have formed, broken apart, and crashed together again.

• Landmasses
• Oceans

The densest part of the plant Earth is the

• core
• mantle
• continental crust
• oceanic crus

Early Earth was intensely hot because of 

• short-lived radioactive decay
• intense bombardment from asteriod impacts
• contraction of materials due to gravity
• all of these

Earth seperated into layers based on

• gravity
• metallicity
• the tendency for material to recycle
• density