Physics - PARTICLE MODEL OF MATTER (P3)

Density -

What is the equation for density?

Density = mass/volume

Density -

What are the units of density, mass, + volume?

Density: kilograms per cubic metre (kg/m³)

Mass: kilograms (kg)

Volume: cubic metres (m³)

Density -

How do you find the volume of an irregular-shaped object?

Submerge it in water + measure the volume of displaced water (displacement method).

Density -

In the required practical, how is density determined for a regular-shaped object?

Measure its dimensions, calculate volume, measure mass, then apply

Density = m/v

Changes of State -

What are the three states of matter?

Solid, liquid, gas.

Changes of State -

What is mwant by a ‘change of state’?

A physical change where a substance changes between solid, liquid, / gas, w/out changing its mass.

Changes of State -

What happens to mass when a substance changes state?

Mass is conserved.

Changes of State -

Name all processes that describe changes of state.

Melting, freezing, evaporating, condensing, sublimating.

Changes of State -

Is a change of state a chemical / physical change?

Physical change.

Internal Energy & Temperature -

What is internal energy?

The total energy of particles in a system due to their kinetic + potential energies.

Internal Energy & Temperature -

What happens to internal energy when a substance is heated?

It increases because the kinetic energy of particles increases.

Internal Energy & Temperature -

What is the difference between temperature + internal energy?

Temperature measures average kinetic energy.

Internal energy is total energy (kinetic + potential).

Specific Heat Capacity -

What is specific heat capacity?

The amount of energy needed to raise the temperature of 1kg of a substance by 1°C.

Specific Heat Capacity -

State the equation for specific heat capacity.

Change in Energy = mass x specific heat capacity x change in temperature

Specific Heat Capacity -

In the required practical, how is the specific heat capacity measured?

Heat a known mass of material w/ a heater, measure temperature change + energy supplied.

Latent Heat -

What is specific latent heat?

The amount of energy needed to change the state of 1kg of a substance w/out changing its temperature.

Latent Heat -

What are the two types of specific latent heat?

Latent heat of fusion (solid <—> liquid)

Latent heat of vaporisation (liquid <—> gas)

Latent Heat -

State the equation linking energy, mass, + specific latent heat.

Energy transferred = mass x specific latent heat

Particle Motion in Gases -

What causes gas pressure?

Collisions of gas particles w/ the walls of a container.

Particle Motion in Gases -

How does increasing temperature affect gas pressure (at constant volume)?

It increases pressure because particles move faster + collide more frequently + forcefully.

Particle Motion in Gases -

What is the relationship between pressure + volume in a gas at constant temperature?

They are inversely proportional.

Particle Motion in Gases -

State the equation for pressure + volume of a gas.

pV = constant

Particle Motion in Gases -

How does doing work on a gas affect its temperature?

Doing work increases internal energy, which raises temperature.

Required Practicals -

Name two required practicals in P3.

Measuring the density of solid + liquid materials.

Determining specific heat capacity of a material.