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 that space is expanding, by Ari's reading?

   • Galaxy redshifts that grow with distance
   • The microwave background's measured temperature
   • The amount of helium
   • Stars twinkling at night
3. 2.

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

   • Light from nearby stars
   • Galaxy redshifts
   • The cosmic microwave background
   • The Milky Way's spiral arms
4. 3.

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

   • The Sun and Earth formed
   • The universe began expanding from a hot, dense state
   • An explosion went off at one spot in an empty, waiting space
   • Galaxies flew out from the Milky Way
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 3,000 K, as when it was released
   • About 270 K
6. 5.

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

   • It was squeezed to shorter wavelengths
   • Expansion stretched it to longer wavelengths
   • It started as microwaves
   • 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)?

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

   • Equal amounts of each element
   • Carbon, then oxygen
   • Hydrogen, then helium
   • Iron, then nickel
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 138 billion years
    • About 13.8 billion years
    • About 4.6 billion years, Earth's age
11. 9.

    Which is older, by Zee's reading?

    • 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
    • The Sun, by about 10 billion years
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 law that cannot be revised
    • An untested idea that scientists have not checked against anything
    • A guess with no evidence
    • A well-tested explanation that fits many observations