Layers of the atmosphere

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   US Standard Atmosphere

   Height (km)	Temperature (°C)	Pressure (hPa)
   0	15.0	1,013.25
   11	-56.5	226.32
   47	-2.5	1.11
   71	-58.5	0.04

2. 1.

   Bo reads four heights from the table. Which layer lies between 11 and 47 km?

   • The thermosphere, where temperature rises with height
   • The troposphere, where temperature rises with height
   • The stratosphere, where temperature rises with height
   • The mesosphere, where temperature rises with height
3. 2.

   Kira climbs from the ground to 100 km. The layers change at about 11, 50 and 85 km. How many boundaries are crossed?

   • Three, at about 11, 30 and 60 km
   • Two, at about 11 and 85 km
   • Three, at about 11, 50 and 85 km
   • Four, at about 11, 50, 85 and 100 km

4. US Standard Atmosphere

   Height (km)	Temperature (°C)	Pressure (hPa)
   20	-56.5	54.75
   32	-44.5	8.68
   47	-2.5	1.11

5. 3.

   Jun reads the table from 20 km up to 47 km. How does the temperature change?

   • It rises 59 °C
   • It falls 54 °C
   • It rises 54 °C
   • It stays the same
6. 4.

   Luz scans all seven rows. At which height is the air coldest, and in which layer?

   • 71 km, in the mesosphere
   • 71 km, in the thermosphere
   • 20 km, in the stratosphere
   • 11 km, in the troposphere
7. 5.

   Temperature rises with height through the stratosphere. What does Milo say heats the air there?

   • Ozone absorbs ultraviolet light and warms the air
   • The layer is closer to the Sun than the layers below it
   • Warm air rising from the ground heats it directly
   • Clouds in the stratosphere release heat as they form

8. Four events and their heights (example)

   Event	Height (km)
   Jet airliner cruising	11
   Weather balloon bursting	30
   Meteor glowing	80
   Space station orbiting	400

9. 6.

   Noah sorts the events by layer. Which event happens in the mesosphere (about 50 to 85 km)?

   • The jet airliner cruising at 11 km
   • The space station orbiting at 400 km
   • The meteor glowing at 80 km
   • The weather balloon bursting at 30 km

10. Ozone by height (example data)

    Height (km)	Ozone (ppm)
    10	0.3
    25	7
    40	5

11. 7.

    Pia finds where ozone is greatest. Which layer holds the most ozone?

    • The stratosphere, where ozone peaks near 25 km
    • The mesosphere, where ozone peaks near 40 km
    • The troposphere, where ozone peaks near 10 km
    • The thermosphere, where ozone peaks near 25 km

12. Dry air by volume (NOAA)

    Gas	Share (%)
    Nitrogen	78.08
    Oxygen	20.95
    Argon	0.93
    Carbon dioxide	0.04

13. 8.

    Tala adds up nitrogen and oxygen. About what share of dry air is neither one?

    • About 0.04%, mostly carbon dioxide
    • About 22%, mostly argon
    • About 1%, mostly argon
    • About 21%, mostly oxygen

14. Use this

    Oxygen is 20.95% of dry air at every height shown. Pressure at 11 km is 226.32 hPa. Partial pressure of oxygen = share × pressure.

15. 9.

    Zee works out how much of the pressure at 11 km is oxygen. What is it?

    • About 4.7 hPa, because the share drops to 2.1% at 11 km
    • About 212 hPa, because 21% of the ground pressure is still there
    • About 226 hPa, because the whole of the air at 11 km is oxygen
    • About 47 hPa, because the share stays near 21% while the pressure falls
16. 10.

    Carbon dioxide is 420 parts per million (ppm) of air. What percent does Esme say that is?

    • 0.0042%
    • 0.042%
    • 4.2%
    • 0.42%