Generalize the changes in thermal energy when matter increases in temperature and then changes state.
When matter increases in temperature, the thermal energy of the substance also increases. This is because temperature is a measure of the average kinetic energy of the particles in a substance. As the particles gain more energy, they move faster and collide with each other more frequently and with greater force, resulting in an increase in thermal energy.
When matter changes state, such as from a solid to a liquid or from a liquid to a gas, there is generally no change in temperature. This is because during a change of state, the energy is used to break the intermolecular forces holding the particles together, rather than increasing the average kinetic energy of the particles.
For example, when ice is heated, its temperature will increase until it reaches its melting point (0 degrees Celsius or 32 degrees Fahrenheit). At this point, the thermal energy of the substance remains constant as the heat energy is used to break the intermolecular forces between the water molecules, leading to a change in state from solid to liquid. Similarly, when water is heated, its temperature will increase until it reaches its boiling point (100 degrees Celsius or 212 degrees Fahrenheit). At this point, the thermal energy remains constant as the heat energy is used to break the intermolecular forces and change the water from a liquid to a gas (water vapor).
In summary, when matter increases in temperature, the thermal energy increases. When matter changes state, there is generally no change in temperature as the energy is used to break the intermolecular forces and facilitate the change in state.