Kinetic Theory

Kinetic Theory: Particles in
Motion

Coach Newman-Honors Physical Science Integrated

What is kinetic energy?

Kinetic Theory of Matter: states that matter is a package of a large number of small
particles, individual atoms, or molecules, which are in constant random motion.

Multiple Choice

True or false, all particles of matter are in motion.

• True

• False

States of Matter

Solid: a state of matter with a definite volume and a definite shape.

Liquid: a state of matter with a definite volume, but NO definite shape.

Gas: a state of matter with NO definite volume and NO definite shape.

Plasma: a state of matter that is superheated gas – so hot that the electrons are
ripped away from the atoms forming an ionized gas

States of Matter

Open Ended

List an example for each of the types of matter we talked about on the previous slide.

Endothermic

Endothermic: a reaction or process in which energy is absorbed as heat by the
system from the surroundings.

Multiple Choice

Which of the following processes or reactions would be endothermic?

• Water freezing

• The chemicals in Hot Hands reacting.

• Water boiling

• Water vapor forming condensation on a soda can on a hot day.

Exothermic

Exothermic: a reaction or process in which energy is released as heat from the
system to the surroundings.

Multiple Choice

Which of the following processes or reactions would be exothermic?

• A log burning in a fireplace.

• A puddle freezing in the winter.

• A block of ice melting.

• A chemical cold pack getting colder after you shake it.

Endothermic vs. Exothermic

Open Ended

Explain what happens to the temperature of an object (the system) and to the temperature of the environment around the object (the surroundings) during an exothermic process.

Phase Changes

Phase Changes: when matter changes to from one state (solid, liquid, gas, plasma)
to another.

Freezing and Melting

Freezing: the process in which matter changes from a liquid to a solid when energy
is removed from the system.

Melting: the process in matter changes from a solid to a liquid as the energy is
added to the system.

Evaporation and Condensation

Condensation: the process in which matter changes from a gas to a liquid when
energy is removed from the system.

Evaporation: the process in matter changes from a liquid to a gas as energy is
added to the system.

Sublimation and Deposition

Deposition: the process in which matter changes directly from a gas to a solid
when energy is removed from the system.

Sublimation: the process in matter changes directly from a solid to a gas as energy
is added to the system.

Open Ended

What is the relationship between endothermic/exothermic processes and phase changes? Explain your answer.