Physics -T3 : the particle model

What are the properties of solids

• fixed shap + volume

• strong attractions between particles

• cannot flow or be compressed

• least kenetic energy

What are the properties of liquids

• fixed volume

• can flow and cannot be compressed

• can change shape

What are the properties of gases?

• can flow and be compressed

• no fixed shape of volume

• most kenetic energy

What happens to kenetic energy as temp increases

The kenetic energy increases as the partciles move faster and overcome forces

density + density equation

• how much of a matter of substance there is in a spce

• density = mass ÷volume

• kg/m³ = kg ÷m³

densiy practical equiptment

measuring cylinds, displacemnt can, objects, mass balence, ruleer

partciles in a gas, what happens when (pressure)…

• as the concentration increases so dows the pressure

• as the temp increses thepressure also increases

• as the volume increases the pressure decareses

what are the partciles in gas equations?

• Pressure x volume = constant

• V1P1=V2P2

what is heat?

a from of energy transfer, from hot to cold

what is temperature

a measure of the average speed of partcles in an object

what is potential energy?

paricles attract and reple eachother, the distace between partciles

solids have strong forces of attraction so high potential energy

gases ahve weak forces of attraction so have low potential energy

What is internal energy

• kenetic + potential energy

• Melting and boiling point are potential energy

• Solids, liquid and gas are kenetic energy

What is specific heat capacity?

The amount of thermal energy needed to increase the temperature of 1kg of a substance by 1 degree

What is the word equation for specific heat capacity?

Change in energy= mass x she x change in temp

What is the unit equation for shc?

J= kg x J/kg •c x *c

What does a large and small shc mean?

• large shc means lost of energy needed to heat substance

• A small shc means the opposite

Pressure equation 1?

pressure = force ÷ area

How does temp increase pressure in gas?

• increase in thermal energy

• Means increase in kenetic energy, so particles move faster

• More frequent collisions with wall of container

• Greater force per unit area exerted and so pressure increases

Work done on gas?

• gas does work so energy put out

• Reduces particle energy: average speed decreases

• Temperature decreases

Specific latent heat?

• the amount of energy needed to change 1kg of a substance from one state to another without changing the temperature

Specific latent heat : heating

• temp does not increase during melting and boiling as energy transferred by heating used for breaking bonds

• Internal energy does increase

Specific latent heat : cooling

• during condensing and freezing bonds form which releases energy, decreases internal energy but temp doesn’t change until the state changes