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Science Test
Earth Unit
Question | Answer |
---|---|
What substances are in earth's second atmosphere? | Water vapor, nitrogen, and carbon dioxide |
What substances are in earth's first atmosphere? | Helium, and hydrogen |
What substance do living organisms give to the atmosphere? | Oxygen |
What are the earliest life forms similar to? | Bacteria |
What is a comet? | A ball of dust and ice that orbits the sun |
What galaxy is the earth in? | The Milky Way Galaxy |
What galaxy is closest to earth? (closest other galaxy) | Andromeda |
What star is closest to earth other than the sun? | Proxima Centuri (4.2 light years away) |
What is the distance that a star travels in a year? | Light Year |
When did the Precambrian begin? | 4.6 billion years ago |
When did accretion begin? | 4.6 billion years ago |
When did Cambrian begin? | 544 million BP |
What is accretion? | The process of forming the earth through gravity causing matter to come together |
What is molten? | Melted; when something is in liquid form |
What forms when the surface rock cools? | The crust |
What sinks to the center of the earth forming the core? | The heaviest metals |
What transforms the planet to become a molten planet? | Heat from accretion |
What causes matter to come together | Gravity |
When did Precambrian end? | 544 million BP |
When did Pangaea occur? | 150,000,000 BP |
When was the last ice age advance? | 17,000 BP |
How long did accretion last? | 100,000,000 years Began 4.6 billion years ago |
What is the age of the earth? | 4.6 billion years old |
Why is the interior of the earth hot? | 1)The friction in the core 2)Heat from accretion trapped by crust 3) The matter inside earth's core |
What forms the crust? | The cooled rock on earth's surface |
Why are iron and nickel the most predominant elements of the core? | The most dense |