Why a gas pushes on its container

Grade 8 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Ari's balloon is warmed, and it stretches to a bigger size while its pressure stays about the same. Why?

   • Warming added particles to fill it
   • The particles got bigger to fill the space
   • Faster hits, but fewer in more space
   • Balloons can't change pressure
2. 2.

   A sealed syringe of air is warmed. What could Bo do with the plunger to keep the pressure the same?

   • Nothing: warming can't change pressure
   • Pull it out to give more room
   • Push it in to give less room
   • Hold it still
3. 3.

   A gas is cooled and squeezed into less space at the same time. Could its pressure stay the same, Esme?

   • Yes: softer hits, but more of them
   • No: cooling must lower it
   • Yes: the particles shrink and grow
   • No: squeezing must raise it

4. Read this first

   Example data

   trial	space	temperature	pressure
   1	1 L	20 °C	200 kPa
   2	2 L	20 °C	100 kPa
   3	2 L	60 °C	114 kPa

5. 4.

   Jun wants to see the effect of the space alone. Which two trials should be compared?

   • Any two trials
   • Trials 1 and 3
   • Trials 1 and 2
   • Trials 2 and 3
6. 5.

   Kira wants the effect of temperature alone. Which two trials should be compared?

   • Trials 1 and 3
   • Trials 2 and 3
   • Trials 1 and 2
   • No pair of them
7. 6.

   Milo says gas expands when warmed because each particle gets bigger. Agree or disagree?

   • Disagree: particles move faster, not grow
   • Agree: warm particles swell up
   • Disagree: gas shrinks when warmed
   • Agree: heat stretches each particle bigger
8. 7.

   Noah says a sealed bottle's pressure can't change unless gas is added or let out. Agree or disagree?

   • Agree: sealed means nothing changes
   • Agree: pressure depends on the amount of gas alone
   • Disagree: pressure changes by itself
   • Disagree: warming or squeezing changes it
9. 8.

   Pia says heating a sealed box raises its pressure because heat makes new gas particles. Agree or disagree?

   • Agree: the hot box breaks particles in two
   • Disagree: heating lowers pressure
   • Agree: heat makes new particles
   • Disagree: the same particles move faster
10. 9.

    Ren wants a drawing of a gas at very high pressure in a small box. Which drawing fits best?

    • A few dots with short motion lines
    • A few giant dots filling the box
    • Many dots resting still on the floor
    • Many dots close together, long motion lines
11. 10.

    A squeezed-gas drawing shows smaller dots than before. How should Zee fix it?

    • Draw the dots stuck to the walls
    • Draw extra dots from squeezing
    • Make the dots smaller still
    • Same-size dots, closer together