11th grade Mass and energy: E = mc² worksheet

Mass and energy: E = mc²

Grade 11 Science Worksheet

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

1. 1.

   Deuterium and tritium (total mass 5.030151 u) fuse into helium-4 and a neutron (total 5.011268 u). With 1 u = 931.494 MeV, what energy is released, to 0.01 MeV, Ari?
2. 2.

   In the Sun's core, four hydrogen-1 atoms (total 4.0313 u) end up as one helium-4 atom (4.002603 u). With 1 u = 931.494 MeV, what energy is released, to 0.01 MeV, Bo?
3. 3.

   One uranium-235 nucleus and a neutron (total 236.052595 u) split into barium-141, krypton-92 and three neutrons (235.866571 u). With 1 u = 931.494 MeV, what energy is released, to 0.01 MeV, Esme?
4. 4.

   Why do both fusion of light nuclei and fission of heavy nuclei release energy, Jun?

   • Both of them create new mass from nothing
   • Both make more tightly bound nuclei
   • Both destroy protons
5. 5.

   Which of these nuclei is among the most tightly bound per nucleon, Kira?

   • Iron-56
   • Hydrogen-2
   • Uranium-238
6. 6.

   Why can't iron be used as fuel for fusion or fission, Luz?

   • It is near the peak of binding
   • It is magnetic
   • Its nuclei are far too heavy to change
7. 7.

   The Sun gives out 3.828 × 10²⁶ W (NASA). Where does that energy come from, Milo?

   • Mass lost in fusion
   • Burning like a fire
   • Shrinking as it cools
8. 8.

   A hot cup of water cools down. What happens to its mass, by E = mc², Pia?

   • It rises a lot
   • It drops, too little to weigh
   • It drops by a gram or more
9. 9.

   Which process joins nuclei, and which splits them, Ren?

   • Both of them split nuclei
   • Fusion joins; fission splits
   • Fission joins; fusion splits
10. 10.

    Why is fusion hard to achieve on Earth, Zee?

    • Fusion needs uranium
    • Hydrogen is too rare
    • Nuclei must be very hot to get close