Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:thermochemistry/x2613d8165d88df5e:thermal-energy-and-equilibrium/v/thermal-energy-temperature-and-heat Thermal energy refers to the kinetic energy of randomly moving particles in a substance. Particles can have translational, rotational, and/or vibrational kinetic energy, depending on the state of matter. Temperature is a measure of the average kinetic energy of the particles in a substance. Heat is thermal energy that transfers into or out of a system. Heat can transfer by conduction, convection, or radiation. Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help! Donate or volunteer today! Donate here: https://www.khanacademy.org/donate?utm_source=youtube&utm_medium=desc Volunteer here: https://www.khanacademy.org/contribute?utm_source=youtube&utm_medium=desc