Simple Kinetic Molecular Model of Matter

Molecules are compacted

Strong intermolecular forces of attraction

Molecules can only vibrate

static and cannot be compressed

Molecules close to each other, but in random arrangements

Weak-ish intermolecular forces of attraction

takes the shape of given space, cannot be compressed

Molecules furthest apart in random arrangements and movements

very weak intermolecular forces

completely fills given space and can becompressed

gas molecules move quickly in many directions via collisions with other gas molecules

as temperature increases, average kinetic energy and speed of molecules does too

molecules bounce off wall and change directions, velocity and momentum changes

if temp. increases, pressure increases so molecules collide faster with walls.

if vol. increases, pressure decreases since molecules collide less with the walls.

liquid surfaces slowly turn to gas due to higher energy within molecules

remaining molecules have lower average kinetic energy aka lower temperature.

to increase the rate of evaporation, one must...

Evaporation cools body that touches evaporating liquid (i.e. sweaty skin because liquid absorbs energy from body so that it can evaporate.

When solid is heated, molecules vibrate more but stay in place, so expansion span is relatively small.

When liquid is heated, it expands like a solid, but intermolecular forces are weaker so it expands more.

When gas is heated, molecules move further apart quickly, so expansion span is the widest among all states.

specific heat capacity: amount of energy required to raise temperature of 1kg of substance by 1°C. (∆𝐸=𝑚𝑐∆𝑇)

thermal capacity: how much energy needs to be put in to raise temperature by given amount. (𝒕𝒉𝒆𝒓𝒎𝒂𝒍 𝒄𝒂𝒑𝒂𝒄𝒊𝒕𝒚 = 𝒎𝒄)

... occurs when energy is put in to a body without a change in temperature.

melting point: temperature at which solid will melt when heated.

boiling point: temperature at which liquid will turn into a gas when heated.

condensation: gas molecules come together from lack of energy to become liquid.

freezing: liquid molecules slow down and bond to become more compacted and solid.

evaporation: different to boiling because it occurs at any temperature on liquid surface

amount of energy needed to change the state of 1kg of a substance.

SLH of fusion = energy to melt/freeze

SLH of vaporization = energy to boil/condense

energy = mass × specific latent heat

has two different metals that meet

temperature difference between them causes small voltage which causes current flow

if temperature increases, so does current.

used for constantly varying high temperatures

the liquid expands/contracts as temperature rises/falls.

expansion amount can be matched to temperature range.

Sensitivity = change in length/change in temperature (use bigger bulb/narrower bore to increase sensitivity)

Range = difference between maximum and minimum temperatures (use wider bore/longer stem to increase range)

Linearity = change in temperature causes same change in length. (kyk ratio gitu)

thermal energy in solids/liquids can be transferred via conduction.

non-metals = poor conductors/insulators. ; metals = good conductors.

thermal energy in fluids can be transferred via convection.

... when molecules in fluid with high thermal energy move to area with low thermal energy.

e.g. water boilers and hot air balloons.

thermal energy transferred via infrared radiation (part of the electromagnetic spectrum); doesn’t require medium.

black object with dull texture = best absorbers and emitters of radiation.

white bodies with shiny texture = best radiation reflectors

temperature and surface area increases = more infrared radiation emitted.