topic 3- particle model of matter

What is density

A measure of how much mass a substance has per unit of its volume

Density equation

Density(kg/m³) = mass(kg)/ volume(m³)

Describe the particles in a solid

Strong forces of attraction, regular fixed arrangement, vibrate in fixed position

Describe the particles in liquid

Weaker forces of attraction, irregular arrangements, move in random directions at low speeds

Describe the particles in a gas

Almost no forces of attraction, free to move and travel in random directions at high speeds

Which state of matter is the most dense

Solids

Which states of matter can flow

Gases and liquids

Which state of matter is easily compressible

Gases

What is internal energy

The total energy stored by the particles making up a substance or system

What does heating a substance do to the internal energy and why

Heating substance transfers energy to the kinetic energy store of all the particles and so increases their internal energy leading to an increase in temperature

What does the size of a temperature change depend on

Specific heat capacity and energy input

What happens if a substance is heated enough and why

Particles will have enough energy in their kinetic energy stores to break the bonds holding them together leading to a change in state

What is name for a solid turning to a gas

Sublimating

What type of change is a change in state

Physical

What do the flat spots on a heating graph mean

It’s where energy is being transferred by heating but not being used to change the temperature

What is latent heat

The energy needed to change the state of a substance

What is specific latent heat

The amount of energy needed to change 1kg of a substance from one state to another without change in temperature

What is specific latent heat of vaporisation

The energy change when a substance changes between a liquid and gas

What is specific latent heat of fusion

The energy change when a substance changes between a solid and liquid

What is the equation for specific latent heat

E(J) = m(kg) x L(J/kg)

When do (gas) particles exert a force

Whenever they collide with the walls of a container so they create pressure

What does the total pressure depend on

How many collisions there are and how much energy each collision involves

What is the effect of an increase in temperature to pressure and why

Increases kinetic energy store leading to particles moving faster and so there are more collisions with the walls of the container causing an increase in pressure

What is the effect of an increase in concentration to the pressure

Increase in number of particles whilst volume is kept the same means there are more particles to collide with the walls leading to more collisions resulting in a higher pressure

What is the effect of a decrease in volume to pressure

More collisions as there’s less distance to travel between each collision resulting in an increase in pressure

What is the relationship between pressure and volume

Inversely proportional (pV = constant)

What is the effect of applying a force (doing work) on a gas

Increases its internal energy which can increase its temperature