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9th grade Earth's early air and oceans worksheet

6 printable versionsBuilding Confidence10 questions · answer keyFree · no account

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Earth's early air and oceans

Grade 9 Science Worksheet - Building Confidence

NameDate

Circle the best answer.

  1. Timeline ruler at 4.6 billion years ago with volcanoes giving off gas. Where did most of Earth's earliest atmosphere come from, by Ari's reading (Smithsonian)?

    • Air left over from the Sun's surface
    • Rain from the oceans
    • Gases from volcanoes
    • Oxygen from forests

  2. Carbon dioxide, water vapor, methane and others. Which gas was almost missing from Earth's early air, by Bo's reading (Smithsonian)?

    • Water vapor
    • Oxygen gas
    • Carbon dioxide
    • Methane

  3. Carbon dioxide then and now. How much carbon dioxide did the earliest air hold compared with today's, by Kira's reading (Smithsonian)?

    • One-tenth of today's
    • About the same as today
    • Ten to 200 times as much as today
    • No carbon dioxide

  4. Drawing of cyanobacteria in shallow water. What first made oxygen gas on Earth, by Jun's reading (Smithsonian, NASA)?

    • Breathing animals
    • Lightning
    • Volcanoes
    • Cyanobacteria, by photosynthesis

  5. Carbon dioxide + water + sunlight → sugar + ? What does photosynthesis give off, by Luz's reading?

    • Volcanic ash
    • Carbon dioxide
    • Methane
    • Oxygen

  6. Why could water not collect on Earth's surface at first, by Noah's reading (Smithsonian)?

    • The surface was too hot until it cooled
    • There was no water anywhere
    • Oxygen blocked the rain
    • The oceans were frozen into the core

  7. Which list names sources of Earth's water, by Pia's reading (NASA, Smithsonian)?

    • The Sun's light turning into water
    • Oxygen from cyanobacteria
    • Melting of the iron core
    • Volcanic water vapor and ice from impacting bodies

  8. Drawing of an icy body striking young Earth. NASA says some icy bodies that hit Earth came from beyond Jupiter and Saturn. What did their ice do, by Ren's reading?

    • It formed Earth's iron core
    • It made the oxygen in the air as it melted
    • It melted and helped make the oceans
    • It froze Earth solid

  9. Read this first

    Oxygen in the air over time (Smithsonian, NASA)

    TimeOxygen in the air
    before about 2.7 billion years agoalmost none
    about 2.4 billion years agofirst fills the air (NASA)
    about 600 million years agoabout one-fifth of today's level
    today21%

  10. About what share of today's air is oxygen, by Zee's reading (Smithsonian, NASA)?

    • About 21%
    • About 78%
    • About 1%
    • About 100%

  11. The young Sun was only about 70% as bright as today. Why didn't Earth freeze over, by Esme's reading (Smithsonian)?

    • Greenhouse gases trapped enough heat
    • It did freeze solid for billions of years
    • The Sun was brighter than today
    • Oxygen in the air kept it warm
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9th grade Earth's early air and oceans worksheet – printable
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About this worksheet

Earth's early air and oceans. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can describe Earth's first air (volcanic gases, rich in carbon dioxide, no oxygen gas) and where the ocean water came from.
  • I can explain how cyanobacteria's photosynthesis raised oxygen, why it took hundreds of millions of years, and what redbeds show.
  • I can read the oxygen timeline and explain how greenhouse gases kept the young Earth warm under a dimmer Sun.

Standard: HS-ESS2-7

Words to know

outgassing: Gases released from inside Earth by volcanoes

cyanobacteria: Tiny photosynthesizing microbes that made the first oxygen gas

Great Oxidation Event: When oxygen first filled the air, about 2.4 billion years ago

redbeds: Rock layers reddened by iron oxide, a sign of oxygen

greenhouse gas: A gas that traps heat, such as carbon dioxide or methane

Common mistakes

Your child pictured early Earth's air with oxygen like today's. Smithsonian: the earliest air came mainly from volcanic gases, and there was no oxygen gas for a long time.

Your child named volcanoes as the oxygen source. Volcanoes gave water vapor and carbon dioxide; free oxygen came from photosynthesis by cyanobacteria (Smithsonian, NASA).

Your child reversed photosynthesis. It takes in carbon dioxide and water with sunlight and gives off oxygen.

Questions parents ask

What is the most common mistake with earth's early air and oceans?

Your child pictured early Earth's air with oxygen like today's. Smithsonian: the earliest air came mainly from volcanic gases, and there was no oxygen gas for a long time.

Are these 9th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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