Kinetic molecular theory of gases

Answer Key - Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   A sealed box of air goes from 280 K to 350 K. Average kinetic energy is proportional to kelvin temperature. By what factor does it change, to 0.01, Kira?

   1.25 times
2. 2.

   Which is a claim of kinetic molecular theory, Jun?

   • Gas particles sit still until the gas is heated
   • Gas particles move fast, in random straight lines
   • Gas particles fill most of the space in a container
3. 3.

   In kinetic molecular theory, how much of a gas's volume do the particles themselves take up, Luz?

   • Very little; a gas is mostly empty space
   • Most of it; the particles touch
   • Nearly the whole volume, once heated particles swell
4. 4.

   In kinetic molecular theory, what happens to the particles' total kinetic energy when they collide, Milo?

   • It drops, so the particles slowly come to rest
   • It stays the same: the collisions are elastic
   • It goes into making the particles bigger
5. 5.

   What causes the pressure inside a balloon, Noah?

   • The particles swelling against the rubber
   • Gas particles hitting the inside of the balloon
   • The weight of gas particles resting on the bottom
6. 6.

   Air is pumped into a bike tire at the same temperature. Why does the pressure rise, Pia?

   • Each particle grows bigger in the tire
   • More particles hit the walls each second
   • The particles stop and press on the walls
7. 7.

   A sealed syringe's plunger is pushed in at the same temperature. Why does the pressure rise, Ren?

   • The particles stop moving and pile up
   • The particles get bigger when squeezed
   • The same particles hit the walls more often in less space
8. 8.

   What does a gas's kelvin temperature measure, Tala?

   • The average kinetic energy of its particles
   • How many particles it has
   • The size of its particles
9. 9.

   At 0 K, what would gas particles' average kinetic energy be in kinetic theory, Zee?

   • Zero, but the particles would be at their largest size
   • Zero, since energy follows kelvins
   • The same as at room temperature
10. 10.

    Why must kinetic energy comparisons use kelvins, not °C, Esme?

    • Kelvins measure the particles' size
    • Celsius numbers are too small to divide
    • Kelvins start at zero energy, so ratios make sense