Physics, 2, Thermal Physics

Front 1

Characteristic properties of solids

Back 1

-fixed shape

-fixed volume

-do not lose shape unless deformed by force beyond their elastic limit

Front 2

Characteristic properties of liquids

Back 2

-fixed volume

-change their shape to fit container (flow)

-molecules move about in contact with each other, don't stay in fixed positions

Front 3

Characteristic properties of gases

Back 3

-no fixed volume or shape

-can be compressed or expanded to change its volume (flow)

-much less dense than solids or liquids

-molecules are far apart, move very rapidly and only make contact when the molecules collide

Front 4

Molecular structure of solids

Back 4

-strong forces of attraction between molecules

-each molecule vibrates about a mean position that is fixed

-when heated, molecules gain energy and vibrate more

-if heated sufficiently, solid melts bc molecules have gained enough energy to break away from the structure

Front 5

Molecular structure of liquids

Back 5

-molecules in contact with each other and move around each other

-still forces of attraction, but these are not strong enough to hold liquid in rigid structure (no fixed shape)

-liquid heated, molecules gain enough energy to break away and become a gas

Front 6

Molecular structure in a gas

Back 6

-molecules much further apart, this is why density is less than that of a liquid

-forces of attraction are negligible

-molecules move about at high speeds, colliding with each other and internal surface of container

-molecules heated, gain kinetic energy and move faster, causing pressure to increase bc molecules collide with container surface more

Front 7

Interpret the temperature of a gas in terms of themotion of its molecules

Back 7

-temperature of a gas increases because its molecules gain more kinetic energy

-average speed of molecules increases

-cooling a gas lowers average speed of molecules

Front 8

Describe qualitatively the pressure of a gas in termsof the motion of its molecules

Back 8

-molecules in a gas collide repeatedly with each other and surface of container

-each impact with surface exerts a tiny force on the surface

-many of these impacts happen which cause a steady pressure on the surface

Front 9

Explain pressure in terms of the changeof momentum of the particles striking thewalls creating a force

Back 9

?

Front 10

Show an understanding of the random motion ofparticles in a suspension as evidence for the kineticmolecular model of matter

Back 10

?

Front 11

Brownian Motion

Back 11

-random molecular bombardment

Front 12

Show an appreciation that massiveparticles may be moved by light, fast movingmolecules

Back 12

?

Front 13

Give a simple molecular account of conduction in solids including latticevibration and transfer by electrons

Back 13

?

Front 14

Define specific heat capacity

Back 14

specific heat capacity of a substance is the heat required to produce a 1°C rise in 1kg

Front 15

Change in energy =

Back 15

Front 16

Thermal capacity equation

Back 16

Front 17

What does convection take place in?

Back 17

gases and liquids

Front 18

Why does convection occur?

Back 18

due to circulation (convection) currents within the substance

fluids rise when heated (get less dense too)

fall when cooled (get more dense)

Front 19

What does convection do?

Back 19

transfers thermal energy from the hotter parts to the cooler parts

Front 20

Why do liquids and gases rise when heated?

Back 20

most expand when heated

particles move about more and take up more volume

density decreases

so it rises

Front 21

What happens when a metal rod is heated?

Back 21

conduction