Topic 3 - Particle Model of Matter Flashcards
What are the four states of matter?
Solid, liquid, gas and plasma
Describe a solid
Strong forces of attraction keeping particles in a fixed arrangement meaning they have high densities
Describe a liquid
Weaker forces of attraction meaning that particles can move around but they have to touch one another, they move randomly and at low speeds, they have lower densities
Describe a gas
Almost no forces of attraction meaning that particles move around freely, randomly and quickly, creating force when they collide with one another - least dense
What is density?
A measure of how much matter is in a set amount of space
What two things affect density?
Mass and volume
Define internal energy?
The amount of energy in a system stored by the particles within it
How do particles store energy?
Kinetic energy stores
What three things affect temperature changes?
Mass, specific heat capacity and energy input
Why does an increase in temperature cause a change in state?
The particles convert the thermal energy into kinetic energy, when they gain enough kinetic energy they are able to break the strong bonds of attraction and change state
What is the conservation of mass rule?
Mass cannot be created or destroyed
What are the five state changes?
Between solid and liquid: melting + freezing
Between liquid and gas: boiling or evaporating + condensing
Between solid and gas: sublimating
T/F: a change in state is a chemical change
False: it is a physical change
Define specific latent heat
The amount of energy needed to change the state of 1kg of a substance
What are the two types of specific latent heat and what do they measure?
Specific latent heat of fusion measures the change between a solid and liquid, whether it is melting or freezing
Specific latent heat of vaporisation measures the change between liquid and gas, whether is it evaporating, boiling or condensing
Why don’t we use a thermometer to measure a change in state?
There is no temperature change during state changes
What is the equation that links energy, mass and specific latent heat?
Energy = mass X specific latent heat
How are kinetic energy of particles and the temperature of substance related?
They are directly proportional
How is pressure created?
When particles in a gas collide with one another or a surrounding surface they exert a small amount of force, this force builds up and causes pressure
Why does an increase in temperature mean an increase in pressure if the volume is kept constant?
When you increase the temperature, you increase the kinetic energy of the particles, this means that they move about faster, exerting more force and collide more often, exerting more force
How are volume and pressure related (assuming a constant mass)?
They are inversely proportional - an increase in volume means a decrease in pressure
Why does doing work on a force increase the temperature?
- Doing work by applying a force increase internal energy, therefore increasing temperature
- Doing work mechanically transfers energy to the kinetic energy of particles, therefore increasing temperature
