particle model of matter

what is density?

the measure of the compactness of an object

what is the equation for density?

Density = Mass/Volume [ρ=m/V]

what is the arrangement and motion of a solid?

- strong forces of attraction hold the particles close together in a fixed regular arrangement

- the particles do not have much energy hence only vibrate around a fixed position

- highest density as particles are very close together

what is the arrangement and motion of a liquid?

- weaker forces of attraction meaning most particles are close together but can move past each other forming irregular arrangements

- more energy than solids so particles can move in a random directions at a low speed

- generally less dense than solids

what is the arrangement and motion of a gas?

- almost no forces of attraction meaning particles are not close together forming a completely irregular arrangement

- particles have lots of energy hence move in random directions at high speeds

- less dense than liquids- lowest density

what is internal energy?

the total energy stored in the particles' kinetic and potential energy stores

what does heating the system do?

transfers energy to it's particles; they gain energy in their kinetic energy stores and move faster ; increasing the internal energy

what does increasing internal energy do?

change in temperature or change in state

if temp changes, what does the size of the change depend on?

mass of the substance, what it is made of and the energy input

when does a change in state occur?

if the substance is heated enough - the particles will have enough energy in their kinetic energy stores to break the bonds holding them together

what is specific latent heat?

the amount of energy required to change the state of 1 kg of a substance without changing its temperature

what is specific latent heat of vaporisation?

The specific latent heat for changing between a liquid & a gas

what is the specific latent heat of fusion?

The specific latent heat for changing between a solid & a liquid

what is the formula for specific latent heat?

E= mL

what does increasing temp of a gas relate to?

the average energy in the kinetic energy stores of the gas particles. The higher the temp, the higher the avg energy

how is pressure created?

Collisions between particles of a gas and the walls of the container cause the pressure in a closed container of gas.

what is the outward gas pressure in sealed container?

total force exerted by all the particles per unit area of the container walls

what will increasing temp do to pressure if volume is constant?

increasing temp will lead to more kinetic energy which will lead to faster particles which will lead to more forceful collisions with container walls which will lead to higher average force per unit area increasing pressure

what will increasing volume do to pressure if temp is constant?

increasing volume means particles are more spread out, meaning they will collide with container walls less frequently, meaning less avg force per unit area of container walls leading to less pressure

what is the equation for pressure if mass and temperature are fixed?

pV = constant

pressure is measure in pascals

what happens when you do work on a gas?

Increase its internal energy which can increase its temperature