Motion energy and stored energy of particles

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   With k = 1.380649 × 10⁻²³ J/K, a gas particle's average kinetic energy is (3/2)kT. At 300 K, what is it in zeptojoules (1 zJ = 10⁻²¹ J), Ari?

   6.21 zJ
2. 2.

   With k = 1.380649 × 10⁻²³ J/K, a gas particle's average kinetic energy is (3/2)kT. At 400 K, what is it in zeptojoules (1 zJ = 10⁻²¹ J), Bo?

   8.28 zJ

3. Read this first

   Three aluminum blocks (example data)

   Sample	Mass (kg)	Temperature (°C)
   A	0.5	80
   B	5	40
   C	5	80

4. 3.

   Using the table, in which samples do the particles move fastest on average, Jun?

   • Samples A and C, both at 80 °C
   • Just sample C, since it has more mass
   • Just sample A, since it is smallest
5. 4.

   Using the table, which sample has the most thermal energy, Kira?

   • C: as hot as A, with 10 times the mass
   • B, since it is large
   • A, since it is as hot as C
6. 5.

   Milo says a large pot of warm water and a small cup of the same warm water have the same thermal energy. Agree or disagree?

   • Disagree: the pot has more particles
   • Agree: thermal energy depends on the container
   • Agree: same temperature means same thermal energy
7. 6.

   Noah says a 5 kg block at 40 °C is hotter than a 0.5 kg block at 80 °C, since it has more thermal energy. Agree or disagree?

   • Agree: heavier objects are hotter
   • Agree: more thermal energy means hotter
   • Disagree: temperature measures average particle motion
8. 7.

   Pia says the particles in a solid don't move at all. Agree or disagree?

   • Agree: particle motion stops when a liquid freezes
   • Agree: solids hold their shape, so their particles are still
   • Disagree: they vibrate about fixed positions
9. 8.

   Why does the pressure of a gas in a sealed, rigid can rise when the gas is warmed, Ren?

   • More particles are created inside the can by the heat
   • The particles grow bigger
   • Faster particles hit the walls harder and more often
10. 9.

    A squeezed spring launcher is released and launches a ball. What happens at the particle scale, Tala?

    • The spring's particles are used up
    • Particle potential energy turns into the ball's motion
    • The spring's particles get heavier
11. 10.

    Why does melting ice take in energy even though its temperature stays at 0 °C, Zee?

    • It pulls particles apart
    • The energy speeds up the particles
    • The energy is destroyed as the ice melts