kinetic theory
an explanation of how particles in matter move
thermal energy
the total kinetic and potential energy of all the particles in a substance.
temperature
average kinetic energy of a substance
in most substances, as temperature increases
the kinetic energy and disorder of the particles increase
thermal expansion
the expanding of matter when it is heated
water expands
when it changes from a liquid to a solid
amorphous solids
no definite melting point
liquefy over a temperature range
liquid crystals
maintain some geometric order in the liquid state
3 assumptions of kinetic theory
1. all matter composed of small particles
2. particles re in constant motion
3.particles are constantly colliding
movement of particles of solids
vibrate in place
movement of particles of liquids
slide past each other
movement of particles of gases
move freely and randomly and collide with one another
describe the movement of particles at the melting point of a substance
particles gain enough kinetic energy to slip out of their ordered arrangement
describe the movement of particles at the boiling point of of a substance
particles in the liquid overcome the downward pressure and escape from the liquid
would the boiling point of water be higher or lower on the top of a mountain peak
lower because atmosphere pressureis lower.
how would the boiling point be affected in a pressurized boiler system
higher, the pressurized boiler system creates a higher pressure above the liquid
boil cup of soup for lunch, drop ice cube in to cool down. how many states of matter are there. how are these states alike and different.
steam from soup = gas
ice cube= solid
soup = liquid
alike in that all composed of water molecules.
different in the amount of kinetic energy the molecules contain and the distance between the particles.
how are kinetic energy and temperature related
temperature is the average kinetic energy of the particles of a substance
why do liquids flow
the particles have gained enough kinetic energy to partially escape the attractiveforces in the solid
what is heat of fusion
the amount of energy required to change a substance from the solid state to the liquid state at its melting point
heat of vaporization
the amount of energy required for the liquid at its boiling point to become a gas
how does external pressure affect the boiling point of a liquid
at greater atmospheric pressure (lower elevation) the boiling point is a higher temperature than at less atmospheric pressure (higher elevation)
diffusion
spreading of particles throughout a given volume until they are uniformly distributed. Diffusion occurs in solids and liquids but occur most in gases.
plasma
matter consisting of positively and negatively charged particles.
2 examples of amorphous solids
glass and plastic