Key Idea: The amount of thermal energy an object has depends on the temperature and the mass of the object and the material of which the object is made.
Students should know that:
- Every object, regardless of whether it is a solid, a liquid, or a gas, and regardless of whether it feels warm or cold to the touch, has some thermal energy even if the object’s temperature is very low.
- The amount of thermal energy an object has depends on the temperature and the mass of the object and the material of which the object is made, and the amount of thermal energy an object has depends on these three factors alone (assuming constant pressure).
- For objects that are made of the same material and have the same mass, the object with the highest temperature has the most thermal energy and the object with the lowest temperature has the least thermal energy.
- For objects that are made of the same material and at the same temperature, the object with the greatest mass has the most thermal energy and the object with the least mass has the least thermal energy.
- Objects that are made of different materials may have different amounts of thermal energy even if they have the same mass and temperature.
Boundaries:
- In assessment items, students are expected to compare relative temperature and masses to determine relative amounts of thermal energy. Assessment items do not ask students to use formulas, such as 3/2 kT and m(ΔT)c, to calculate thermal energy.
- Items do not assess the idea that heat capacity is a measure of how much the temperature of an object will increase with the addition of a given amount of thermal energy, or why an object could feel colder than other objects at the same temperature.
- Items do not assess students’ knowledge of which specific types of materials have more thermal energy than others. Students are only expected to know that equal amounts of different materials may have different amounts of thermal energy.
- In assessment items, the temperature changes are limited to those that do not involve changes of state.
- Assessment items may use either Fahrenheit (ºF) or Celsius (ºC) as the units of temperature.
- The idea that temperature is independent of mass is covered under a different idea (Temperature is not a characteristic property of substances).
- Students are not expected to know the difference between “weight” and “mass.” The words “weight” or “weigh” are used as substitutes for “mass” in situations where such substitutions do not make any difference. When two objects are compared, they are in the same gravitational system.
| Item ID Number |
Knowledge Being Assessed | Grades 4–5 |
Grades 6–8 |
Grades 9–12 |
Select This Item for My Item Bank |
|---|---|---|---|---|---|
58% | 50% |
66% |
|
||
51% | 56% |
59% |
|
||
All things have thermal energy, not just warm things, hot things, and things that are not frozen. | 25% | 55% |
62% |
|
|
49% | 39% |
38% |
|
||
29% | 39% |
44% |
|
||
43% | 43% |
34% |
|
||
36% | 30% |
28% |
|
||
A living person, a living plant, a dead plant, and a penny all have thermal energy. | 14% | 31% |
38% |
|
|
34% | 24% |
25% |
|
||
A living person, a dead plant, and a penny all have thermal energy. | 16% | 23% |
32% |
|
Misconception |
Student Misconception |
Grades 4–5 |
Grades |
Grades |
|---|---|---|---|---|
75% | 61% |
50% | ||
27% | 42% |
44% | ||
Inanimate objects do not have any thermal energy (Herrmann-Abell & DeBoer, 2010). | 37% | 33% |
28% | |
51% | 41% |
40% | ||
Objects at 0ºF/0ºC do not have any thermal energy (AAAS Project 2061, n.d.). | 22% | 17% |
14% | |
14% | 14% |
15% | ||
Only very hot things like the sun have thermal energy (AAAS Project 2061, n.d.). | 31% | 12% |
7% | |
Cold/frozen objects do not have any thermal energy (AAAS Project 2061, n.d.). | 15% | 13% |
12% | |
28% | 32% |
34% | ||
The amount of thermal energy an object has decreases as the temperature of the object increases. | 15% | 12% |
9% | |
When comparing two objects at the same temperature the smaller object has more thermal energy. | 20% | 16% |
15% |
Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.