Why a gas pushes on its container

Grade 8 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari's science card asks what makes a gas push on the walls of its box. Which answer is right?

   • The gas resting its weight on the floor
   • Particles sticking to the walls
   • Particles growing until they touch the walls
   • Particles hitting the walls
2. 2.

   Bo's balloon stays round and firm. Why?

   • The balloon is full of solid air
   • Air particles keep hitting the rubber from inside
   • The air particles swell up to fill it
   • The rubber pulls itself outward
3. 3.

   Box A and box B hold the same number of particles. A's particles move fast; B's move slowly. Which has the higher pressure, Esme?

   • Box B, as slow particles push longer
   • The same: same number of particles
   • Box A
4. 4.

   A sealed, rigid box of air is warmed. What happens to the particles inside, Jun?

   • They slow down
   • They get bigger
   • New particles appear
   • They move faster
5. 5.

   Then what happens to the pressure in the warmed, sealed box, Kira?

   • It goes down, as warm gas is lighter
   • It goes up
   • It drops to zero
   • It stays the same: no gas was added
6. 6.

   Why does squeezing a gas into less space raise its pressure, Noah?

   • Squeezing makes more particles
   • The walls get heavier
   • Particles get squashed smaller
   • Particles hit the walls more often
7. 7.

   Pia seals the tip of a syringe and pulls the plunger out, giving the air more room. What happens to the pressure inside?

   • It stays the same: same air inside
   • It goes up
   • New air particles appear
   • It goes down

8. Read this first

   Example data

   temperature	pressure
   20 °C	100 kPa
   40 °C	107 kPa
   60 °C	114 kPa

9. 8.

   Ren reads the gauge table for a sealed, rigid tank as it warms. What happens to the pressure?

   • It rises
   • It falls
   • It doubles each row
   • It stays at 100 kPa: same gas
10. 9.

    Each 20 °C step adds about 7 kPa. What reading would Tala expect at 80 °C?

    • About 228 kPa
    • About 107 kPa
    • About 100 kPa
    • About 121 kPa
11. 10.

    Zee's table shows a gas at one temperature in two sizes of container. What happened when the space was halved?

    • The pressure halved
    • The pressure doubled
    • The pressure dropped to 0 kPa
    • The pressure stayed the same