PHASE CHANGES

KINETIC THEORY OF MATTER

Matter is made up of particles which are in continual random motion.

WHAT ARE THE 4 STATES OF MATTER?

SolidSolidPlasmaPlasma

GasGas

LiquidLiquid

SOLIDS:• Solids have a definite shape and volume

• usually organized, crystalline solidcrystalline solid

• Softer solids will have no pattern, amorphous solidamorphous solid.

• packed tightly together• Vibrate in place

PARTICLES IN LIQUIDS:• Liquids have a definite volume

• Liquids take the shape of their container.

• Liquids are a fluid • Far enough apart to slide over one another

• Energy level is greater than in solids

PARTICLES IN GASES:• No definite volume or

shape.• Gasses spread out to fill the entire space given.

• Can be squeezed together• Particles are very far apart and move freely

• Collide frequently• Have LOTS of energy

PARTICLES IN PLASMA:

• Plasma is a lot like a gas, but the particles are electrically charged.

• Have indefinite shape and volume.

• EXTREMELY energetic• Lightning is a plasma.• Used in fluorescent light

bulbs and Neon lights.

STATES OF MATTER

SOLID LIQUID GAS PLASMA

Tightly packed, in a regular

patternVibrate, but do not move from place to place

Close together with no regular arrangement.Vibrate, move

about, and slide past each other

Well separated with no regular arrangement.Vibrate and

move freely at high speeds

Has no definite volume or shape

and is composed of electrical charged

particles

WHAT IS A PHASE CHANGE?

• A change from one state of matter to another

• Phase changes are physical changes because they do not affect the chemical make up of a substance.

WHAT HAPPENS DURING A PHASE CHANGE?

• During a phase change heat energy is either absorbed or released

• Heat energy is released as molecules slow down and move closer together- exothermicexothermic

• Heat energy is absorbed as molecules speed up and expand-endothermicendothermic

MELTING

• Phase change from a solid to a liquid

• Molecules speed up, move farther apart, and absorb heat energy

FREEZING

• Phase Change from a liquid to a solid

• Molecule slow down, move closer together and release heat energy.

VAPORIZATION (BOILING)

• Phase change from a liquid to gas. It occurs at the boiling point of matter.

• Molecules speed up, move farther apart, and absorb heat energy.

EVAPORATION

• Phase change from a liquid to a gas on the surface of a liquid (type of vaporization).

• Molecules speed up, move farther apart, and absorb heat energy.

CONDENSATION

• Phase change from a gas to a liquid.

• Molecule slow down, move closer together and release heat energy.

SUBLIMATION

• Phase change from a solid to a gas.

• Molecules speed up, move farther apart, and absorb heat energy.

DEPOSITION

• Phase change from a gas to a solid.

• Molecules slow down, move closer together and release heat energy.

PHASE CHANGE OF WATER1. Why is there no

change in temperature during a phase change?

2. Define melting and boiling point.

3. What is the melting and boiling point of water?

4. At what temperature does water freeze and become a solid?