Kinetic Molecular Theory States of Matter Phase 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 water Dust particles in air Gold hammered into foil Oil spreading on the surface of water Condensation 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 Curve Gas to Liquid to Solid

Heating Curve Solid to Liquid to Gas

Summary

BrainPop Quiz Phases of Matter