HEAT temperature and thermal energy are all con cerned with microscopic movements within matter These movements are explained by what is called the kinetic theory of matter MoLECULES IN MoTION All matter whether a solid liquid or gas is composed of tiny particles such as molecules and atoms These particles are constantly in motion traveling vibrating or rotating randomly in all directions One of the many different forms of energy is the energy some thing has because of its motion This type of energy is called kinetic energy The kinetic energy of the particles in matter is the basis of temperature thermal energy and heat Temperature is the measurement of how fast on average the particles in something are moving Microwaving a bowl of soup for example raises the temperature of the soup by speeding up the average motion of its molecules The molecules in the hot soup are traveling faster overall than they did before the soup was heated The molecules in an ice cube are moving more slowly Temperature is thus a measure of inten sity It does not depend on the quantity of matter being considered An ice chip and 12
WHAT IS HEAT A diagram of an atom with electrons orbiting a nucleus All matter is composed of atoms which although invisible to the human eye move and vibrate constantly creating kinetic energy Mushakesa Shutterstock com 13
HEAT a brick of ice will have the same tempera ture if the average speed of their particles is the same Thermal energy on the other hand repre sents the total amount of kinetic energy of an objects molecules and other particles A hot bowl of soup has more thermal energy than a cold bowl of soup because the total amount of its particles motion is greater However Although this Antarctic iceberg is cold to the touch it has a great deal of thermal energy because of the combined motion of all of its particles It thus bas the potential to give of far more beat than a much smaller bowl of soup even if the soup feels piping bot Volodymyr Goinyk Shutterstock com 14
WHAT IS HEAT a hot bowl of soup possesses more thermal energy than a cup of soup at the same tem perature Likewise an iceberg has far more thermal energy than a piping hot bowl of soup The iceberg is so much larger than the bowl of soup that the sum of the motion of all its particles is greater than that of the soup This is true even though the soup has a higher temperature Temperature is a mea sure of the overall speed of the particles motion thermal energy of the total energy they have because of their motion Thermal energy represents the amount of heart that something could potentially give off Heat is the transfer of thermal energy from a hotter substance to a colder one Transferring heat to a substance usually raises its temperature ACHIEVING BALANCE If a hot poker is plunged into cold water the poker becomes cooler and the water becomes warmer This means that the hot body gives up some of its heat to the cold body The molecules in the water speed up and the water gains energy at the same time those in the poker slow down and the poker loses energy The exchange of heat will continue 15
