The evidence for the Big Bang

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Table, Evidence for the Big Bang (NASA, ESA), with columns Observation, What it shows

   Galaxy redshifts grow with distance, space is expanding; microwave background at about 2.7 K, a hot, dense early universe; mostly hydrogen and helium, a little lithium, early element-making.

2. 1.

   Which observation shows the early universe was hot and dense, by Bo's reading?

   • Light from nearby stars
   • Galaxy redshifts
   • The Milky Way's spiral arms
   • The cosmic microwave background
3. 2.

   In the Big Bang model, what happened about 13.8 billion years ago, by Kira's reading (NASA)?

   • The Sun and Earth formed
   • An explosion went off at one spot in an empty, waiting space
   • The universe began expanding from a hot, dense state
   • Galaxies flew out from the Milky Way
4. 3.

   Timeline from the Big Bang with an early mark. About when was the cosmic microwave background released, by Jun's reading (NASA)?

   • When the Sun formed
   • About 380,000 years after the Big Bang
   • Recently, given off by the stars in our own galaxy
   • About 13.8 billion years after the Big Bang
5. 4.

   Thermometer scale from 0 K to 10 K. What is the cosmic microwave background's temperature today, by Luz's reading (ESA Planck)?

   • About 2.7 K
   • About 5,800 K, like the Sun
   • About 270 K
   • About 3,000 K, as when it was released
6. 5.

   Why is the background light now in microwaves, not visible light, by Milo's reading?

   • It started as microwaves
   • Expansion stretched it to longer wavelengths
   • It was squeezed to shorter wavelengths
   • It comes from cold stars

7. Table, Evidence for the Big Bang (NASA, ESA), with columns Observation, What it shows

   Galaxy redshifts grow with distance, space is expanding; microwave background at about 2.7 K, a hot, dense early universe; mostly hydrogen and helium, a little lithium, early element-making.

8. 6.

   Which elements does the Big Bang model say formed in the first minutes, by Noah's reading (NASA)?

   • Just iron and gold
   • The whole periodic table, formed in one blast
   • Carbon, oxygen and iron
   • Hydrogen, helium and a little lithium
9. 7.

   Pie chart of atoms in the oldest gas (sources give 92 to 95% hydrogen). Most atoms in the oldest gas clouds are which elements, by Pia's reading?

   • Iron, then nickel
   • Equal amounts of each element
   • Carbon, then oxygen
   • Hydrogen, then helium
10. 8.

    Timeline ruler in billions of years. About how old is the universe, by Tala's reading (NASA, ESA Planck)?

    • About 13.8 million years
    • About 4.6 billion years, Earth's age
    • About 138 billion years
    • About 13.8 billion years
11. 9.

    Which is older, by Zee's reading?

    • The Sun, by about 10 billion years
    • The Sun, which is about three times older than the universe
    • The universe, about three times older than the Sun
    • They are the same age
12. 10.

    Three evidence lines pointing to one explanation. In science, what does it mean to call the Big Bang a theory, by Esme's reading?

    • A guess with no evidence
    • An untested idea that scientists have not checked against anything
    • A well-tested explanation that fits many observations
    • A law that cannot be revised