Simple kinetic molecular model of matter Flashcards
the physical properties of solid liquid gas
solid: fixed shape and volume; incompressible
liquid: no fixed shape but fixed volume; incompressible
gases: no fixed shape nor fixed olume; compressible
particle arrangements of solid liquid gas
solid: usually in fixed pattern
liquid: no fixed pattern
gas: no fixed pattern
inter particle distance of solid liquid gas
solid: close 10^-10m
liquid: close 10^-10m
gas: far apart 10^-7 or ^-6)
inter particle forces of solid liquid gas
solid: very strong
liquid: weak
gas: negligible
particle speeds of solid liquid gas
solid: vibrating about fixed position
liquid: sliding over each other
gas: moving about at high speeds
what is temperature
temperature is the speed of a particle
what determines the state of matter(solid liquid gas)
inter-particle forces
what does inter-particle forces do
they are what keeps molecules ibn their fixed positions.
how does matter change form
once the molecules gain sufficient energy, they overcome the inter-particle forces and start to slide over / break free from each other and start to move at high speeds
equation relationship between pressure temperature and volume
pv = nRT
P = pressure
V = volume
n = amount of substance
R = ideal gas constant(0.0821)
T = temperature
amonton’s law
a change in pressure of a fixed mass of gas at constant volume is caused by a change in temperature of the gas
T∝P
charles law
a change in volume of a fixed mass of gas at a constant pressure is caused by a change in temperature of the gas
temp change->volume change
V∝T
boyle’s law
a change in pressure of a fixed mass of gas at constant temperature is caused by a change in volume of the gas
P∝1/V
for all the laws to work what is one criteria that all scenarios need
fixed mass of gas
amonton’s law equation
P1/T1 = P2/T2
they should usually have 3 of 4 in the qn
boyle’s law equation
P1V1 = P2V2
they should usually have 3 of 4 in the qn
charle’s law equation
V1/T1 = V2/T2
they should usually have 3 of 4 in the qn
how to know when to use amonton’s law
when theres a fixed volume, and fixed mass of gas
fixed mass of gas is a must for all 3 laws
fixed V, cuz this law test for P n T
how to know when to use boyle’s law
when theres fixed temperature, and fixed mass of gas
fixed mass of gas is a must for all 3 laws
fixed T, cuz this law test for P n V
how to know when to use charle’s law
when theres fixed pressure, and fixed mass of gas
fixed mass of gas is a must for all 3 laws
fixed P, cuz this law test for V n T
what is thermal equilibrium
2 points r consider to be in thermal equilibrium if there is no net flow of thermal energy when they are connected by a path permeable to heat
NOT AFFECTED BY VOLUME
50kg of water to 50deg <=> 0.50kg of water to 50deg
what is thermal energy
its basically the same as temperature which is basically the same as kinetic energy of the particles
Temperature increase → Thermal energy increase → Particles’ kinetic energy increases → Particles move faster.
temperature real meaning
average kinetic energy of particles in an object
what are emitters and absorbers
all objects constantly absorb and emit radiation. hence, we must consider the net flow of energy,
net emitter of radiation: emits radiation at a faster rate compared to absorption
net emitter of radiation: absorbs at a faster rate compared to emission
radiation meaning
the transfer of thermal energy in the form of electromagnetic waves, such as infrared radiation, without the aid of a medium.
conduction meaning
conduction is the transfer of thermal energy through a medium without any flow of the medium
particles at a region of higher temperature vibrate vigorously about their fixed positions. they then collide with with neighbouring particles to transfer kinetic energy to particles at regions of lower tempertaure, until thermal equilibrium is reached. As a result, energy is transferred with no transfer of particles
why are liquids and gases poor conductors of heat compared to solids?
the particles in liquids and gases are spaced further apart than those in solids.
the frequency of collisions is thus lower in liquids and gases. hence, the rate of energy transfer by collisions between particles is lower. as a result, the rate of conduction is lower in liquids and gases, making them poor conductors of heat compared to solids
why are solids metals better conductorss of heat than solid non-metals?
metals are better conductors of heat than non-metals due to the presence of free electrons that are able to *move around the medium freely**, which increases the rate of thermal energy transfer by conduction.
convection meaning
convection is the transfer of thermal energy by means of convection currents in fluids due to a difference in density.
in most fluids, an increase in temperature corresponds to an increase in volume. Hence, when a region of a fluid is heated, it expands and thus density decreases. this region will then rise in the fluid as it is of a lower density compared to its surroundings. regions of higher density sink to occupy the space left behind. this creates a convection current
why does hot gas/liquid rise
molecules in the gas/liquid move faster and spread out, increasing the volume of the air. Since density is mass per unit volume, when the air expands, its density decreases.
lower density = rise
surface physical properties that affect thermal heat transfer
-temperature, higher temperatures increase radiant heat transfer
-area, larger areas increase radiant heat transfer
-colour, dark surfaces absorb more solar radiation and reflects less
-texture, shinier surface reduces radiant heat transfer
internal energy meaning
u(IE) = KE + PE
KE = when the object changes temp
PE = when the object changes state (gas,liquid,solid)
when either one of them increases or decreases so does internal energy
eg. gas condensing, PE decreases -> IE decreases
heat capacity definition
Q = C Δθ
Q = the energy required to change the temperature
C = heat capacity
Δθ = temperature change
specific heat capacity definition
Q = m c Δθ
Q = the energy required to change the temperature
c = heat capacity
m = mass of the material
Δθ = temperature change
calculate the amount of heat required for a phase change (like melting, freezing, boiling, or condensation) without a change in temperature.
QL = m l
