User:Inconspicuum/Physics (A Level)/Specific Heat Capacity
It takes energy to heat things up, since heat is work. If we heat a more massive thing up, it takes more work, because we have to give more particles, on average, an energy kT. Some substances require more work to heat up than others. This property is known as specific heat capacity. This gives us the formula:
,
where ΔE is the work put in to heating something up (in J), m is the mass of the thing we are heating up (in kg), c is the specific heat capacity (in Jkg-1K-1), and Δθ is the difference in temperature due to the work done on the substance (in degrees Celsius or Kelvin).
It should be noted that the specific heat capacity changes slightly with temperature, and more than slightly when the material changes state. A table of the specific heat capacities of various substances is given below:
| Substance | State | Temperature (°C) | Specific Heat Capacity (kJkg-1K-1) |
|---|---|---|---|
| Air | gas | 23 | 1.01 |
| Aluminium | solid | 25 | 0.90 |
| Animal (and human) tissue | mixed | 25 | 3.5 |
| Argon | gas | 25 | 0.52 |
| Copper | solid | 25 | 0.39 |
| Glass | solid | 25 | 0.84 |
| Helium | gas | 25 | 5.19 |
| Hydrogen | gas | 25 | 14.3 |
| Iron | solid | 25 | 0.45 |
| Lead | solid | 25 | 0.13 |
| Nitrogen | gas | 25 | 1.04 |
| Oxygen | gas | 25 | 0.92 |
| Uranium | solid | 25 | 0.12 |
| Water | solid | -10 | 2.05 |
| Water | liquid | 25 | 4.18 |
| Water | gas | 100 | 2.08 |