Heat and Thermal Energy Review Quiz Key
1. In order to have a transfer of thermal energy between two objects in contact, they must have different
__temperatures___.
2. Temperature is defined as the (average / total) kinetic energy of the particles.
3. The transfer of thermal energy is called __heat__.
4. If the temperature of a substance rises by 10o C then it must have risen by (more than / less than /
exactly) 10 K and (more than / less than / exactly) 10 oF.
5. Convert the following temperatures:
a. 311 K = __100.4_oF
b. 63 oF = __17.2__ oC
c. 37oC = _310___ K
6. Two steel objects each have 1000 J of thermal energy in them. If object A is at a higher temperature
than object B then object A must have (more / less / the same) mass as compared to object B.
7. Water has a (high / low) specific heat and therefore changes temperature (quickly / slowly). Gold has a
(high / low) specific heat and therefore changes temperatures (quickly / slowly). Based on this, if you
burn your hand, it is better to put it in contact with 1000 g of (water / gold) at room temperature.
8. If objects A and B are only in contact with one another and object A loses 100 J of thermal energy then
object B gains (more than / less than / exactly) 100 J of thermal energy.
9. At the boiling point, what phase or phases of matter exist? _liquid and gas___
10. At the freezing point, what phase or phases of matter exist? __solid and liquid____
11. Lead has a specific heat of 130 J / kg oC and aluminum has a specific heat of 903 J / kg oC. If the same
amount of thermal energy is added to both, the (aluminum / lead) will have a larger increase in
temperature.
12. Heat from the sun travels through the vacuum of space by (conduction / convection / radiation).
13. The classroom is heated by (conduction / convection / radiation).
14. A pot on the stove gets hot due to (conduction / convection / radiation).
15. Thermal energy always moves from (high to low / low to high) temperatures.
16. As a substance changes phase the temperature (increases / decreases / remains the same).
17. As the temperature of a substance increases, the speed of the molecules (increases / decreases / remains
the same), and the kinetic energy of the molecules (increases / decreases / remains the same).
18. The temperature of a substance only changes when it is in (one / two) phase(s).
19. As the entropy of a substance increases, the substance has the ability to do (a larger / a smaller / the
same) amount of work.
20. Two specimens of water are mixed together. If the initial temperature of one is 40 oC and the other is 90
o
C then the final temperature must be (greater than 90 oC / less than 40 oC / between 40 oC and 90 oC)
21. If equal amounts of water at 0 oC and 80 oC are mixed together then the equilibrium temperature will be
_40___ oC.
22. A (solid / liquid / gas) has a definite shape and volume, on the other hand, a (solid / liquid / gas) has a
definite volume but assumes the shape of the container.
23. When an object is heated, the vibration of the molecules (increases / decreases / remain the same).
24. The transfer of energy that doesn’t involve matter moving is (conduction / convection / radiation), the
transfer of energy that involves particles bumping into each other is (conduction / convection /
radiation), and the transfer of energy through the movement of fluids is called (conduction / convection
/ radiation).
25. Changing a solid into a liquid is called (melting / freezing / condensing / boiling), changing a liquid into
a gas is called (melting / freezing / condensing / boiling), changing a gas into a liquid is called (melting
/ freezing / condensing / boiling), and changing a liquid into a solid is called (melting / freezing /
condensing / boiling).
26. When dry ice changes from a solid directly to a gas without going through the liquid phase, this process
is called _sublimation___.
27. At thermal _equilibrium___, the temperature of the objects in contact is the same and there (is / is not) a
flow of thermal energy between them.
28. If 1500 J of thermal energy raises the temperature of 2 kg by 5oC, the specific heat of the substance is
__150____ J/kg oC.
29. If 200 g of brass (specific heat 376 J / kg oC) at 75 oC is placed into 100 g of water (specific heat 4180 J
/ kg oC) at 0 oC, the equilibrium temperature is __11.4___ oC.
30. If 300 g of an unknown substance at 50 oC is placed into 100 g of water (specific heat 4180 J / kg oC) at
100 oC and they reach an equilibrium temperature of 90 oC. The specific heat of the unknown substance
is _348.3__ J / kg oC.
31. Five hundred grams of lead are raised 100 m and dropped, if the specific heat of lead is 130 J / kg oC and
all of the potential energy is converted into thermal energy then the lead will increase in temperature by
_7.54__ oC.
32. The boiling point for isopropyl alcohol is _80__ oC.
33. The melting point for isopropyl alcohol is _-90__ oC.
34. At - 20 oC, isopropyl alcohol is a (solid / liquid / gas).
35. At – 120 oC, isopropyl alcohol is a (solid / liquid / gas).
36. At what temperature can isopropyl alcohol be either a liquid or
a gas? __80 oC___.
37. At what temperature can isopropyl alcohol be either a solid or a liquid? __-90 oC___.