Kinetic Molecular TheoryStates of MatterPhase Changes

Kinetic Molecular Theory # 1

Matter is composed of small particles (molecules). The measure of space that the molecules occupy (volume) is derived from the space in between the molecules and not the space the molecules contain themselves.

Evidence

Food coloring in waterDust particles in airGold hammered into foilOil spreading on the surface of waterCondensation of water vapor by

increased pressure

Kinetic Molecular Theory #2

The molecules are in constant motion. This motion is different for the 3 states of matter. Solid – vibrate in

position Liquid - Molecules

will flow or glide over one another, Motion is a bit faster than solid

Gas – Molecules move freely of each other and at a greater speed

Kinetic Molecular Theory # 3

When the molecules collide with each other, or with the walls of a container, there is no loss of energy – energy is transferred

Temperature effect on Physical Properties *directly proportional*

Increases Kinetic energy of

particles increases Volume increases Solid changes to

liquid – liquid changes to gas

Viscosity increases Malleability

increases

Decreases Kinetic energy of

particles decreases Volume decreases Gas changes to

liquid – liquid changes to solid

Viscosity decreases Malleability

decreases

Viscosity

Volume

Malleability

To determine if something is malleable – ask the question could it be easily bent or flattened into a sheet

Think about when you first take the play-doh out of the container – Is it easy to work with?

What happens as heat is transferred from your hands?

Is everything malleable? What are examples of things that would be

malleable?

Review

Which would have a greater viscosity – honey or water?

If I decreased the temperature of honey what would happen to the viscosity? If I increased the temperature of honey what would happen to the viscosity?

What does malleable mean?Give one example of evidence to prove

that matter is in constant motion.

BrainPop

States of Matter

Liquid

Fixed volume – takes the shape of the container

Close together, but in a random pattern

Moving faster than a solid, but slower than a gas

Solid

Fixed volume and shape

Packed together in a pattern

Vibrate in position

Gas

No fixed shape or volume – spread out to fill the container

widely spaced out Move rapidly,

frequently colliding with each other and the side of the container

BrainPop Quiz

States of Matter

BrainPop

Phases of Matter

Solid to Liquid

Heat is added – kinetic energy increases and weakens attractive forces between particles

At the melting point the solid melts into a liquid

Liquid to Gas

Heat is added to the liquid – kinetic energy increases and weakens attractive forces between particles

begin to boil when reach the boiling point temp increases particles move even faster and over

come the attractive forces and evaporate forming a gas

Gas to Liquid

Heat is lost from the gas – attractive forces become stronger - kinetic energy decreases

when enough heat is given off the particles condense into a liquid

Liquid to Solid

Heat is lost – kinetic energy decreases and increases attractive forces between particles

At the freezing point the liquid becomes a solid

Sublimation

When a solid changes directly into a gas without melting

EX: smaller ice cubes in the back of the freezer

Cooling CurveGas to Liquid to Solid

Heating CurveSolid to Liquid to Gas

Summary

BrainPop Quiz

Phases of Matter