Kinetic Theory of Matter Chapter 16 Section 1 Part A Kinetic Theory of Matter

Kinetic Theory Explains how particles behave Three basic ideas: All matter made of small particles All particles are in constant motion Particles collide Collisions transfer energy

Kinetic Energy Remember, kinetic energy is the energy of motion KE = ½ m v2 Since all particles are moving, all particles have kinetic energy Temperature is the measure of the AVERAGE kinetic energy of particles in matter

Potential Energy Particles also have potential energy Potential energy is stored energy May be due to gravity, chemical nature

Thermal energy Thermal energy is the total energy in matter Thermal energy is the sum of kinetic and potential energy of the particles Thermal energy determines the state of matter

States of Matter Five recognized states of matter The state depends on the balance between kinetic and potential energy of the particles The states: Solid Liquid Gas Plasma Bose-Einstein Condensate

Solid Particles close together Usually packed in a particular pattern (crystal) Particles vibrate in place, do not move apart As a result: Definite volume Definite shape

Liquid Particles not as close as solid Do not have regular pattern Particles move and slide past each other As a result: No definite shape Definite volume

Gas Particles free to move away from each other Particles constantly collide and bounce away As a result: No definite shape No definite volume

Plasma Extremely high energy rips electrons away from atoms Interaction of ionic particles Example: any star, lightning

Bose-Einstein Condensate Proposed by Satyendra Nath Bose and Albert Einstein in the 1920s First created and observed in 1995 First accomplished by Eric Cornell and Carl Wieman in Boulder, Colorado BEC Homepage Gaseous superfluid cooled to near absolute zero All atoms can flow past one another behaving almost like a synchronized wave 

Phase Transitions Changing kinetic energy causes a change in the state of matter Change from liquid  gas: vaporization Change from gas  liquid: condensation Change from liquid  solid: freezing (crystallization) Change from solid  liquid: melting Each of these changes requires a specific amount of kinetic energy change

Phase Transitions Change from gas  liquid (or vice versa) requires change in energy Heat of vaporization: specific amount of energy required to change the particle distance and motion from gas to liquid Change from solid  liquid (or vice versa) requires change in energy Heat of fusion: specific amount of energy required to change the particle distance and motion from solid to liquid

Phase Transitions Melting point (freezing point): Boiling point: Temperature at which the substance changes from liquid to solid (or vice versa) Boiling point: Temperature at which the substance changes from liquid to gas (or vice versa)

Phase Transitions Not all substances change state in an orderly way Amorphous solids: solids with no orderly particle structure Liquid crystals: keep orderly particle structure even as a liquid