P3 Particle Model Of Matter Flashcards
Describe solid particles
Strong forces of attraction
Fixed regular arrangement
Vibrate around fixed positions
Dense
Describe liquid particles
Weaker forces of attraction Close together but can move Irregular arrangement Move in random directions at low speeds Less dense
Describe gas particles
No forces of attraction
More energy, free to move
Constantly moving in random directions and speeds
Not very dense
What creates pressure and how
Colliding gas particles
When colliding they exert a force on each other/object, increasing pressure
In a sealed container the outward gas pressure is the total force exerted by all particles in a gas on a unit area
What happens if you increase the temperature of gas particles
More energy transferred to kinetic energy stores of particles, increasing speed. Therefore the pressure increases as the particles are colliding more and have a larger momentum (larger force when colliding)
What is density
Measure of the compactness of a substance.
Relates to substance mass to how much space it takes up
What does density depend on
What the object is made of and how are particles are arranged
Dense = tightly fitted particles
Less dense = particles spread out
Compressed material is more dense
Density of a solid object - how to work out
Measure width height length and find volume and measure mass. Density = mass/volume
Work out volume of irregular object
Submerge in eureka can - displaced water is the volume. Measure mass. Density = mass/volume
Work out density of liquid
Measuring cylinder on a balance.
Pour 10ml of liquid and record mass.
Add 10ml more and repeat measuring each time until cylinder is full. Use Formular to find each density and find average. Density = mass/volume
What is internal energy
The energy stores by the particles that make up a system (particles move or vibrate, which makes up the energy in the kinetic energy store)
What is the internal energy of a system
It’s the total energy that it’s particles have in their kinetic and potential energy store
How is energy stored in a system
Stored by its particles
What do heating systems transfer to. What does this lead to
They transfer energy to particles, increasing internal energy. This leads to temperature or state change.
What does the temperature change of an object depend on
Depends on the mass, what it’s made of and energy input
Name the state changes
Melting is solid to liquid
Freezing is liquid to solid
Evaporation is liquid to gas
Condensing is gas to liquid
Sublimating is solid to gas
Deposition is gas to solid
What is a state change
Physical change in a different form. Particles are arranged differently. Mass is conserved
What happens during a state change
Energy increases, increasing internal energy
What is the energy in state changes(melting or boiling)used for
Used to break intermolecular forces rather than raising temperature. Temperature increases once state has changed
What happens during condensing or freezing
Bonds are forming, which releases energy so internal energy decreases but temperature doesn’t go down until state is fully changed
What is latent heat
The energy needed to change the substances state
What is specific latent heat
Energy needed to change the state of a 1kg ass without changing temperature
Key facts of specific latent heat
For cooling, SLH is the energy releases
SLH is different for different material
SLH for solids and liquids is specific latent heat of fusion
SLH between liquid and gas is specific latent heat of vaporisation
Energy(J) = mass x specific latent heat (J/kg)
