How is temperature related to the average kinetic energy of molecules that make up a substance?
In gases, temperature is a measure of, and proportional to, the average translational kinetic energy of molecules and atoms. In solids and liquids, the situation is more complicated, but average kinetic energy does increase with temperature. There is still some "zero point" kinetic energy at absolute zero.
Temperature is related to the average kinetic energy of molecules that make up a substance through the kinetic theory of gases. This theory states that the temperature of a substance is directly proportional to the average kinetic energy of its molecules.
To understand this relationship, we need to understand what kinetic energy is. Kinetic energy is the energy possessed by an object due to its motion. In the case of molecules, kinetic energy is associated with their random motion or vibration.
At higher temperatures, the average kinetic energy of molecules increases. This is because as the temperature rises, the molecules gain more energy, causing them to move faster and collide with each other more frequently and with greater force. Conversely, at lower temperatures, the average kinetic energy of molecules decreases.
The relationship between temperature and average kinetic energy can be explained using the formula for kinetic energy:
KE = (1/2)mv^2
where KE is the kinetic energy, m is the mass of the molecule, and v is its velocity. The velocity of a molecule is directly related to its average kinetic energy. Therefore, as the temperature increases, the average velocity of molecules also increases, resulting in higher kinetic energy.
In summary, temperature and the average kinetic energy of molecules have a direct relationship. As the temperature of a substance increases, so does the average kinetic energy of its molecules, leading to increased molecular motion and faster collisions between molecules.