solids, liquids and gases 5 Flashcards
why does heating a system change the energy stored within the system and raise its temperature or state?
heat energy is needed to increase the temperature of an object. the amount of energy needed depends on the masses of an object, type of material it is made from and the temperature increase.
how do objects change state?
SOLID > melts > LIQUID > evaporates/boils > GAS
GAS > condenses > LIQUID > solidifies/boils > SOLID
whats the arrangement of particles in a solid?
close together
a fixed, regular pattern
- strong forces of attraction hold particles close together
whats the movement of particles in a solid?
vibrate on the spot
whats the arrangement of particles in a liquid?
close together
irregular arrangement
- weak forces of attraction between particles
whats the movement of particles in a liquid?
move around each other
random directions
low speeds
- more energy than solid particles
whats the arrangement of particles in a gas?
far apart
random arrangement
whats the movement of particles in a gas?
move quickly in all directions
high speeds
- no forces of attraction between particles
- most energy
practical
show the constant temperature during a change of state:
equipment: bunsen burner, beaker, stearic acid (solidifies and liquid) in boiling tubes, thermometer, stopwatch
method for melting - place boiling tube with the sa in a beaker of water
-place on top of bunsen burner
-start stopwatch
-record temperature every minute until the stearic acid turns into a liquid
method for solidifying - place boiling tube and as in a beaker
-record initial temperature
-start stopwatch and record temperature until the entire quantity of stearic acid has solidified
when plotting temperature and energy input what goes on what axis?
x-axis - energy input
y-axis - temperature
during a change of state, temperature stays…
constant
what is temperature?
measure of how hot something is
what is heat?
measure of thermal energy in an object
whats the measure of specific heat capacity?
J/kg degrees
whats the equation for change in thermal energy?
change in thermal energy = mass x specific heat capacity x change in temperature