Latent heat is energy gained or lost when a substance changes state, measured in joules. Molecules move differently in gas, liquid, and solid states, and excess energy is released as latent heat. This energy is felt in sweat evaporating and can cause thunderstorms and hurricanes.
Latent heat is the name given to the energy that is lost or gained from a substance when it changes state, for example from gas to liquid. It is measured as an amount of energy, joules, rather than a temperature.
Most substances can exist in three states: gas, liquid and solid, although there is an additional state called plasma. The main difference between a substance in any state is the speed at which its molecules move. Like a liquid, molecules move at a speed where they can repeatedly join, break apart, then join again. When they move slowly, they stick together, forming a solid. When they move fast, they stay broken, forming a gas.
For example, we usually think of water as a liquid. However, it can also be a solid (ice) or a gas (vapour). But as you can see when you boil water in a kettle or when the surface of a pond freezes over, not all molecules in a substance change states at the same time.
When a molecule changes state, it has a different amount of energy. However, the laws of physics state that energy cannot simply disappear. Then, as the molecule moves more slowly, the excess energy is released into the surrounding environment as latent heat. When the molecule is moving faster, it has absorbed extra energy by absorbing latent heat from its surroundings.
You can feel the effects of latent heat on a hot day as sweat evaporates from your skin and you feel cooler. This is because the liquid molecules that evaporate will need more energy when they become water vapor. This thermal energy is taken from the skin, reducing its temperature.
The effects of latent heat are also visible over time. When the water molecules in the air rise high enough, they get colder and condense into a liquid that has less energy. The “reserve” energy becomes latent heat and makes the surrounding air hotter. This leads to wind, and when the process happens quickly, it can even cause a thunderstorm.
Latent heat also provides the energy for hurricanes and cyclones, which start over warm oceans where there is a large amount of warm, moist air that can rise and then condense. The warmer the air, the more energy produced by cooling and condensation, which is why hurricanes are more likely and more powerful in warmer seasons.
Protect your devices with Threat Protection by NordVPN
