Kinetic Theory of matter

Kinetic theory of matter

1) All matter is made up of tiny particles (atoms, molecules)

2) These particles are always in motion3) The hotter the temperature of the

substance, the faster the particles move 4) At the same temperature, more massive

particles move slower than less massive particles

Big concepts

• particles are in constant motion (they always have energy to use)

• Amount of energy involved with particles in object can determine it’s state of matter

• Energy and mass are conserved

WHAT TYPE OF ENERGY DO PARTICLES HAVE?

RUB YOUR HANDS TOGETHER, THEN PLACE THEM ON EITHER SIDE OF THE FACE OF YOUR PARTNER

What is energy?Are there different types of energy?

Energy• Definition: Having energy allows an object to do

work on itself, other objects or the surrounding environment. Work involves motion of changing of temperature

• Types• Gravitational potential energy (GPE)• Kinetic Energy (KE)• Elastic Potential energy (EPE)• Non-mechanical energy (TE, EE, LE…)

Types of energy

• GPE, based on their position. However because atom’s mass is so small, an atom’s GPE is negligible

Kinetic Energy

• The energy associated with movement. Atom’s motion can be significant on it’s own scale

Motion on microscopic scale is felt as heat on our scale

Therefore kinetic energy associated with the motion of particles is called Thermal energy

Thermal energy

• Increase in heat increase in kinetic energy

• Increase in heat increase in motion of atoms

Amount of thermal energy in an object

• Depends on:

The amount of motion of each particle

The number of particles that make up the substance

Thermal energy may not uniformly distributed in an object

Thermal Energy and temperature

• This is a type of non-mechanical energy

• The thermal energy of an object is equal to the total kinetic energy of the atoms in the object.

• Temperature is the measure of the average kinetic energy of the object

Temperature and heat

• Temperature and heat are related but not the same concept

• Heat is the transfer of energy from higher energy particles to lower energy particles.

Temperature

• Is not related to how much material is in the object but related to the amount of energy in each particle of the object

Temperature and motion of particles

• The lower the temp, the slower the particles

• Absolute zero (-273°C) all particle motion stops

• What place can obtain a temp. reading of absolute zero?

HOW CAN SOLIDS CAN HAVE MORE THERMAL ENERGY THAN GASES?

• More atoms in a smaller space

• Total amount is more, but amount per atom is less

STATES OF MATTER AND ENERGY

Connections between energy and state of matter

Greater energy means less rigid attachment between atoms/molecules

The hotter the object is, the more energetic its atoms and molecules are

The hotter the object is, the less attached the atoms and molecules are to each other

States of matter

• States of matter are physically different

• Solids, liquids and gases differ in:– The amount of energy in each particle

– This affects:• distance between atoms/molecules• How tightly connected are atoms/molecules

Solids

• Particles are tightly bound to other particles

• Positions in the object are fixed

• The motion of particles is limited to vibration

Liquids

• Particles move more rapidly than solids

• Particles can slide past each other, not as tightly bound

• A greater freedom of motion, but not uninhibited

Gases

• Fastest particles

• Nearly impossible to bind particles together

• Uninhibited (will go anywhere that is possible)

Relating state of matter and object’s shape, volume,

particle’s speed and energy

Solid Liquid gas

shape Definite Defined by

container

Defined by container

volume Definite Definite Defined by container

speed slow faster fastest

energy Least per particle

More per particle

Most per particle

Changes in states of matter

• Require a change in the kinetic/thermal energy of the particles that make it up