thermal

Question 1

1 mole

Answer 1

the amount of material so the number of basic particles is 6*10^23 (avogadro’s constant)

Question 2

molar mass

Answer 2

mass of 1 mole of a substance

Question 3

kinetic model of an ideal gas

Answer 3

the volume of particles negligible compared to volume occupied by gas
forces between particles 0 except during collisions
negligible time in collisions compared to between
random movement
obey newton’s laws (constant velocity between)
elastic collisions (no energy lost)

Question 4

ideal gas equation

Answer 4

PV=nRT (Pressure, Volume by gas, n moles, R gas constant, T temperature in K

Question 5

pressure

Answer 5

force per unit area

Question 6

brownian motion

Answer 6

evidence for the behaviour of an ideal gas
particles are seen to be moving randomly, the change in momentum after collisions with the wall shows a force acting (Newton 2), collisions experienced as an average pressure

Question 7

macroscopic concepts of thermal physics

Answer 7

temperature, internal energy and thermal energy

Question 8

thermal energy

Answer 8

transfer of random kinetic energy between objects as a result of a difference in temperature (energy leaking into/out of objects)
result of collisions of molecules
kinetic energy is shared out by collisions averaging the thermal energy

Question 9

temperature

Answer 9

measure of heat, depends on the kinetic energy of particles

determines the direction of thermal energy transfers

Question 10

internal energy

Answer 10

total potential(due to attractive forces) and random kinetic energy added up over all the individual molecules of an object
depends on substance, temperature, pressure and state of the material

Question 11

phase changes

Answer 11

happens when the particle bonds change
when the bonds break, they immediately reform but with different particles
the higher the temperature, the faster the particles vibrate, and more often that one breaks

Question 12

boiling vs evaporating

Answer 12

evaporation is at the surface when individual particles have enough energy to separate (causes cooling, at greatest rate at larger surface areas, high temp and low surrounding humidity)
boiling is when it happens to large numbers of particles

Question 13

temperature not changing in a phase change

Answer 13

since temperature is the measure of average kinetic energy, at the boiling point the energy supplied does not increase the Ek, but only increases the Ep (distance) between the molecules

Question 14

thermal capacity

Answer 14

the heat required to change the temp of a body by 1K

C=Q/ΔT

Question 15

specific heat capacity

Answer 15

heat needed to raise the temp of 1 kg of material by 1K

Q=mcΔT

Question 16

measuring specific heat capacities

Answer 16

direct (using a heater and thermometer)
method of mixtures (using a mixture of two liquids to create desired one, with one known specific heat capacity, the resulting average can be used to find the other

Question 17

specific latent heat

Answer 17

the heat needed to change 1kg of a material from one phase to another
Q=mL