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
   • Stars twinkling at night
   • The amount of helium
   • The microwave background's measured temperature
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
   • The universe began expanding from a hot, dense state
   • Galaxies flew out from the Milky Way
   • An explosion went off at one spot in an empty, waiting space
4. 3.

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

   • About 270 K
   • About 5,800 K, like the Sun
   • About 2.7 K
   • About 3,000 K, as when it was released
5. 4.

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

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

6. 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.

7. 5.

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

   • Hydrogen, helium and a little lithium
   • The whole periodic table, formed in one blast
   • Carbon, oxygen and iron
   • Just iron and gold
8. 6.

   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
   • Hydrogen, then helium
   • Carbon, then oxygen
9. 7.

   Why do the amounts of hydrogen and helium count as evidence, by Ren's reading?

   • They show the theory is a guess
   • They show galaxies are moving apart
   • They show where stars formed first
   • They match what the early universe should have made
10. 8.

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

    • About 13.8 billion years
    • About 138 billion years
    • About 4.6 billion years, Earth's age
    • About 13.8 million 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
    • They are the same age
    • The universe, about three times older than the Sun
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?

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