chapter 7 Flashcards
brownian motion
random movement of microscopic particles suspended in a liquid/gas
what are the spaces between particles occupied by
not. by matter, but vacuum
matter definition
anything that has mass and takes up space
solid properties
- definite volume
- definite shape
- cannot be compressed
liquid properties
- definite volume
- no definite shape
- cannot be compressed
gas properties
- no definite volume
- no definite shape
- can be compressed
why do solids have definite volume/shape
- particles are very closely packed in an orderly matter
- vibrate about the fixed position
why cant solids be compressed
- there is very little space between particles for them to move closer togethter
how are solids particles held together
- held by very strong forces of attraction
why do liquid have definite volume but not definite shape
- particles are closely packed in a disorderly manner
- move randomly and slide past another
why cant liquid be compressed
- particles closely packed but are further apart than in an solid
- little space between particles for them to move closer together
how are liquid particles held together
- strong forces of attraction
why dont gases have defenite volume/defenite shape
- particles are far apart and arranged in a disorderly manner
- move randomly and quickly
why can gases by compressed
- lots of space between particles to move closer together
how are gases held together
- weak forces of attraction
expansion (solids)
- particles gain energy and vibrate more vigorously about the fixed positions
- increased distance between particles
- causes volume of substance to increase
contraction (solids)
- particles lose energy and vibrate less vigorously about their fixed positions
- decreases distance between positions
- volume of substance decreases
conservation of mass
- number and size of particles stay the smae
change in state
- melting
- boiling
- freezing
- condensation
melting
solid changes into a liquid without a change in temperature
boiling
liquid changes into a gas without a change in temperature
melting explained
- solid is heated, particles gain energy
- vibrate faster in fixed position
- gain enough energy to overcome very strong forces of attraction
- solid melts -> liquids
boiling explained
- liquid is heated, particles gain energy
- move faster and further apart from one another
- gain enough energy to overcome strong forces of attraction
- liquid boils -> gas
condensation explained
- gas is cooled, particles lose energy and move slower
- particles pull close to another by forces of attraction
- gas condenses -> liquid
freezing explained
- liquid is cooled, particles lose energy and move slower
- causes particles to be pulled much closer to another by forces of attraction between them
- particles are eventually held in fixed positions
- liquid freezes -> solid
diffusion
net movement of particles from a region of higher concentration to a region of lower concentration
diffusion explained
1) drop of ink is added into a beaker of water
2) high concentration of ink particles at the bottom of the water
3) ink particles move randomly in various directions until the concentration of the ink particles throughout the beaker in uniform
