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Chapter 3 – States of Matter. 3.1 Solids, Liquids, and Gases. Solids Definite Shape Definite Volume Particles vibrate in fixed positions Particles have low kinetic energy. Liquids Variable shape (takes the shape of the container) Definite Volume Particles can move around each other
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3.1 Solids, Liquids, and Gases • Solids • Definite Shape • Definite Volume • Particles vibrate in fixed positions • Particles have low kinetic energy
Liquids • Variable shape (takes the shape of the container) • Definite Volume • Particles can move around each other • Particles have medium Kinetic Energy
Gases • Variable shape • Variable volume (fills all space in a container) • Particles move about freely • Particles have high Kinetic Energy
Plasma • Exists only at extremely high temperatures • 99% of the matter in the UNIVERSE is plasma • Stars are plasma • Einstein-Bose Condensate • Exists only at extremely low temperatures • Groups of atoms behave as a single particle
Kinetic Theory • Kinetic energy = energy an object has due to its motion • The faster an object is moving; the greater its kinetic energy. • Kinetic theory states that all particles of matter are in constant motion. ** View animation on visual concepts CD
3.2 The Gas Laws • Pressure = the result of force distributed over an area • More Collisions=More Pressure • In a closed container, gases exert pressure when the particles of the gas collide with the walls of the container.
Factors That Affect Gas Pressure • Temperature – raising temp. will increase pressure if volume of gas and # of particles are kept constant • Inc. in temp. part. move faster part. collide with walls more frequently increased pressure
Volume – Decreasing volume of a gas causes an increase in pressure if the temp. and # of part. are constant • Decrease in vol. less space particles collide with walls more often inc. pressure
Number of particles – increasing the number of particles of a gas will increase pressure if temp. and volume are constant • Inc. # of particles particles collide with container more often inc. pressure
Gas Laws • Charles’ Law – volume of a gas is DIRECTLY PROPORTIONAL to temperature • Inc. Temp. x2 Inc. Vol. x2 V1 = V2 T1 T2
Boyle’s Law – volume of a gas is INVERSELY PROPORTIONAL to pressure • Inc. Vol. x2 Dec. pressure by ½ P1V1 = P2V2
Combined Gas Law • The Combined Gas Law – relates temperature, volume and pressure of a gas. • Formula: P1V1 = P2V2 T1 T2
3.3 Phase Changes • Phase change – reversible physical change that occurs when a substance changes from one state of matter to another • Temperature of a substance DOES NOT CHANGE during a phase change. • Energy is either absorbed or released during a phase change. • Endothermic – energy is absorbed • Exothermic – energy is released
Melting and Freezing • Melting • Solid changes to liquid • Particles absorb energy (endothermic) • Particles become less orderly
Freezing • Liquid changes to solid • Particles release energy (exothermic) • Particles become more orderly
Vaporization and Condensation • Vaporization • Liquid changes into a gas • Particles absorb energy (endothermic) • Particles become LESS orderly and more free to move • 2 types of vaporization • Evaporation – takes place at the surface of a liquid • Boiling – occurs when a liquid is heated to its boiling point
Condensation • Gas changes to a liquid • Particles release or lose energy (exothermic) • Particles become MORE orderly
Sublimation and Deposition • Sublimation • Changing from a solid directly to a gas • Energy is absorbed (endothermic) • Deposition • Changing from a gas directly to a solid • Energy is released (exothermic)