Why salt, sugar and copper behave differently

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   Copper melts at 1084.62 °C and sugar at 185.5 °C. In kelvins, how many times higher is copper's melting point, to 0.01, Ari?

   2.96 times
2. 2.

   Table salt melts at 800.7 °C and sugar at 185.5 °C. In kelvins, how many times higher is salt's melting point, to 0.01, Bo?

   2.34 times
3. 3.

   What is broken when salt melts but not when sugar melts, Jun?

   • Electron seas
   • Bonds inside water molecules
   • Attractions between ions
4. 4.

   Why does a copper pan spread heat well, Kira?

   • Its free electrons carry energy
   • Its ions are locked firmly in place
   • It is made of molecules
5. 5.

   Why does sugar melt at a lower temperature than salt, Luz?

   • Its molecules attract weakly
   • Its ions attract strongly
   • It has an electron sea
6. 6.

   Milo says every solution in water conducts electricity. Agree or disagree?

   • Disagree: sugar water doesn't
   • Agree: water carries the current
   • Agree: dissolving makes ions
7. 7.

   Noah says sugar water conducts like salt water because both are clear. Agree or disagree?

   • Agree: clear solutions conduct
   • Disagree: sugar gives no ions
   • Agree: both are sweet
8. 8.

   Which of these is best for electrical wires, Ren?

   • Table salt
   • Copper
   • Table sugar
9. 9.

   Which would make water conduct when dissolved in it, Tala?

   • Copper
   • Table sugar
   • Table salt
10. 10.

    Which substance melts easily on a kitchen stove, Zee?

    • Table salt
    • Copper
    • Table sugar