Kinetic molecular theory of gases

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   Average particle speed is proportional to the square root of kelvin temperature. A gas goes from 300 K to 675 K. By what factor does its average speed change, Esme?

   1.5 times
2. 2.

   Average particle speed is proportional to the square root of kelvin temperature. A gas goes from 250 K to 640 K. By what factor does its average speed change, Kira?

   1.6 times
3. 3.

   Ari says warming air from 20 °C to 40 °C doubles its particles' kinetic energy. Which reply fits, Luz?

   • Agree, if the air is in a sealed balloon
   • Agree: double the temperature, double the energy
   • Disagree: 293.15 K to 313.15 K is about 7% more
4. 4.

   Esme says heated gas particles grow, which is why a warm balloon swells. Which reply fits, Milo?

   • Disagree: the particles speed up and hit the rubber more
   • Agree: hot particles are bigger particles
   • Agree: particle size rises with temperature
5. 5.

   Bo says gas pressure comes from particles resting on a container's floor. Which reply fits, Noah?

   • Agree: the particles settle when they are still
   • Disagree: it comes from particles hitting each wall
   • Agree: the floor holds up the gas's weight
6. 6.

   At the same temperature, about how many times faster do N₂ molecules (28.02 g/mol) move than CO₂ (44.01 g/mol), Ren?

   • About 1.57 times as fast
   • The same speed, at the same temperature
   • About 1.25 times as fast
7. 7.

   Which statement fits gases at the same temperature, Tala?

   • Heavier gases move faster and carry more energy
   • Equal average energy; lighter gases move faster
   • Equal speeds; heavier gases carry more energy
8. 8.

   Which observation best supports gas particles being far apart, Zee?

   • A gas spreads to fill a whole room
   • A sealed syringe of air can be squeezed smaller
   • Air feels cool on a windy day
9. 9.

   Which observation best supports gas particles moving constantly, Ari?

   • A balloon keeps its color
   • A smell spreads through a still room
   • Air can be weighed in a sealed bottle
10. 10.

    Which observation best supports pressure rising with temperature, Bo?

    • A balloon floats on a windy day
    • A bike tire is harder to pump when nearly full
    • A car tire reads higher after a hot afternoon