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?
Solid
Plasma
Gas
Liquid
SOLIDS:
• Solids have a definite shape and volume
• usually organized, crystalline solid
• Softer solids will have no pattern, amorphous 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-exothermic
• Heat energy is absorbed as molecules speed up and expand-endothermic
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?