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?

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

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

   • The cosmic microwave background
   • Galaxy redshifts
   • The Milky Way's spiral arms
   • Light from nearby stars
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
   • An explosion went off at one spot in an empty, waiting space
   • Galaxies flew out from the Milky Way
   • The universe began expanding from a hot, dense state
5. 4.

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

   • About 13.8 billion years after the Big Bang
   • When the Sun formed
   • About 380,000 years after the Big Bang
   • Recently, given off by the stars in our own galaxy
6. 5.

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

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

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
   • Carbon, oxygen and iron
   • Just iron and gold
   • 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?

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

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

    • They match what the early universe should have made
    • They show where stars formed first
    • They show the theory is a guess
    • They show galaxies are moving apart
11. 9.

    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 13.8 billion years
    • About 138 billion years
    • About 4.6 billion years, Earth's 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 well-tested explanation that fits many observations
    • A law that cannot be revised
    • An untested idea that scientists have not checked against anything
    • A guess with no evidence