Solids, Liquids and Gases Chapter 16

Section 1 – Kinetic Theory States of matter you saw at lunch? Kinetic Theory – explanation of how particles in matter behave All matter is composed of small particles (atoms, molecules, ions)

Kinetic Theory Particles in constant, random motion Particles are colliding Energy that particles lose from collisions is negligible

Average Kinetic Energy Temperature is measure of average kinetic energy. Warmer – particles have MORE energy  Move faster Cooler – particles have LESS energy  Move slower

Solid State – H2O Particles in fixed position

Liquid State Particles in solid gain energy and move faster  break out of fixed position Melting point: temperature where solid begins to liquefy Heat of fusion: amount of energy needed to change a solid to liquid

Liquids Flow Particles have energy to break SOME attraction and flow

Gas State Particles have energy to escape ALL attraction

Vaporization Liquid particles gain enough energy to escape to gas phase Evaporation: vaporization at the surface of liquid, spontaneously Boiling point: applying heat, temperature at which pressure of vapor is equal to external pressure, liquid to gas Heat of vaporization: amount of energy needed for liquid to be a gas

Gases fill their Container Diffusion: spreading of particles throughout until they are mixed

Heating Curve of a Liquid

Heating Curve of a Liquid a and c – increasing in energy b and d – energy used to break attraction between particles

Plasma Def: consists of positive and negative particles Very HIGH temperature Particles moving so fast  e- are stripped off Lightning, sun, neon lights

Thermal Expansion

Thermal Expansion Spaces are expansion joints Prevent cracks Absorbs heat – expands Cools – shrinks

Expansion of Matter Thermal Expansion: increase in the size of a substance when the temperature is increased Warmer = less attraction b/ particles = move freer Cooler = more attraction = closer together

Expansion of Matter

Expansion of Matter

Strange Water Ice is less dense than liquid water (+) and (-) ends arrange themselves next to each other Create empty spaces

Strange Water

Solid or Liquid? Amorphous Solids: “without” form, change to liquid over range of temperatures Ex: glass, plastic Liquid turned to solid too quickly

Solid or Liquid Liquid crystals: change to liquid but don’t lose their ordered form Ex: liquid crystal display (LCD)  calculators, etc.

Properties of Fluids Section 2

How do ships float? Buoyancy: ability of fluid to exert upward force on object. If force equal to weight = float

Archimedes’ Principle Def: buoyant force on an object is equal to the weight of the fluid displaced by the object

Density Same size blocks - wood and steel Displace same amount of water BUT, wood block floats and steel block sinks Different densities – object has less density than density of fluid to float

Archimedes’ Principle

Pascal’s Principle Pressure: force exerted per unit area Pressure applied to fluid is exerted throughout the fluid Used in hydraulic lifts – use your weight to lift something much heavier

Bernoulli’s Principle Def: as velocity of fluid increases  pressure of fluid decreases

Fluid Flow Viscosity: the resistance of a fluid to flow Syrup – high viscosity Water – low viscosity

Behavior of Gases Section 3

Pressure Result of gas particle collisions with the container More collisions = More pressure Pressure unit = Pascal (Pa) How do we get high pressure?

Boyle’s Law Relationship between pressure and volume  volume, size of container, what will pressure do? Pressure  Inversely related: as one goes  the other goes  , or vice versa

Charles’s Law Relationship between volume and temperature “Keep away from heat” on pressurized can  temperature what will volume do?  volume Directly related: as one goes  the other goes , or vice versa

Kelvin Scale All (+) numbers 0K = absolute zero – all particle motion stops 0K = -273oC K = oC + 273