Summary
Objects have energy because of their temperatures, and heat is this energy in
transit from one object to another. Temperature is a measure of the
concentration of an object’s internal thermal energy.
When a substance absorbs or gives off heat, either the temperature of the
substance can change, or the substance can undergo a phase change, but not
both.
The change of a substance’s temperature depends upon the specific heat of the
substance and the amount of the substance present. Use the equation Q = mc
∆T.
The temperature of a substance remains constant during the substance’s phase
transition. Use the formula Q = mL.
Heat transfer and thermal expansion are related in that when a substance
undergoes a temperature change, it changes in size.
Because the atoms or molecules that make up a gas move freely and rapidly in
a chaotic swarm, a confined gas exerts a force in the walls of its container. To
find this pressure, use the equation P =.
The ideal gas law, PV = nRT, covers ideal gases, which have the following
properties:
- The volume of the gas molecules is negligible compared to that of
the container which holds them.
- They experience no electrical forces.
- They undergo elastic collisions.
The zeroth law of thermodynamics states that when two objects are brought
into contact, heat flows from the warmer object to the cooler one.
The first law of thermodynamics states that energy (in the form of heat) is
neither created nor destroyed in any thermodynamic system.
