Particle Model of Matter (P3) Flashcards
Define Density
Density is the mass for a given volume
What are the three common states of matter?
Solid
Liquid
Gas
Describe properties of particles in a solid?
Very close together
Arranged in a regular pattern
Vibrate but do not move from place to place
Describe properties of particles in a liquid?
Close together
Not arranged in a regular pattern
Can move around each other
Describe properties of particles in a gas?
Far apart
Not arranged in a regular pattern
Moving very rapidly
Equation for density
ρ=m/v
Density (kg/m^3) = Mass (kg) / Volume (m^3)
What is the density in solids?
Very High
What is the density in liquid?
High
What is the density in gas?
Low
Why does polystyrene have low density?
It has many air spaces
How do we measure the volume of a regular object such as a cube?
Base x Height x Width
How do we investigate the density of a cube?
Measure the mass
Measure the volume (bhw)
Put it into the equation ρ=m/v
How do we investigate the density of a cube?
Measure the mass using a balance
Measure the volume (bxhxw)
Put it into the equation ρ=m/v
How do we investigate the density of an irregular object?
Measure the mass using a balance Fill a Eureka can with water Place the object in the Eureka can Measure the volume of water that leaves the can (same as the volume of the object) Put it into the equation ρ=m/v
Define Internal Energy
The energy stored in a system by the particles
total kinetic and potential energy of all the particles that make up a system
Which types of energy do particles have?
Kinetic
Potential
What do we do to a solid to turn it into a liquid?
Increase the internal energy
Melting
What do we do to a liquid to turn it into a gas?
Increase the internal energy
Boiling
What do we do to a gas to turn it into a liquid?
Reduce the internal energy
Condensing
What do we do to a liquid to turn it into a solid?
Reduce the internal energy
Freezing
What is it called when a solid turns into a gas?
Sublimation
Why is changing states a reversible process?
It is a physical change, not chemical
Define Evaporation
When a liquid turns to a gas but only on the surface of the liquid
Define Specific Heat Capacity
The energy required to raise 1kg of a substance by 1*C
Equation for Specific Heat Capacity
ΔE=mc∆θ
Change in energy (J) = mass (kg) x specific heat capacity (J/kg°C) x change in temperature (°C)
SMILE
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Press 5
What does the heating graph of a solid look like?
Temperature on the y-axis and time on the x-axis
It is a straight line increasing, it then plateaus, increases again, plateau and increases once more.
Define Latent Heat
Energy needed to change the state 1kg of a substance without a temperature change
What does the cooling graph of a gas look like?
Temperature on the y-axis and time on the x-axis
It is a straight line decreasing, it then plateaus, decreasing again, plateau and decreasing once more.
Why does a heating graph have flat sections where temperature does not increase?
Energy being put in is weakening or breaking the forces of attraction, not increasing kinetic energy
What is the specific latent heat of fusion?
Melting
The energy requires to change 1 kg of a substances from a solid to a liquid with no temperature change
What is the specific latent heat of vaporisation?
Boiling
The energy requires to change 1 kg of a substances from a liquid to a vapour with no temperature change
What is the equation for Latent Heat?
E=mL
Energy for a change of state (J) = Mass (kg) x Specific Latent Heat (J/kg)
In which direction do particles in a gas move?
Brownian Motion
Constant Random Motion
Define Pressure
Pressure is the force exerted on the surface of a container per unit of area
How can we increase the pressure of a specific mass of a gas?
Increase temperature
increases average kinetic energy
What is gas pressure at low temperature? Why?
Low
There are few, low energy collisions per second
What is gas pressure at high temperature? Why?
High
There are many, high energy collisions per second
What happens when particles in a gas collide with the inside of a container?
A force acts at right angles to the walls of the gas container
(Outwards)
This is the pressure
The same mass of gas, in a container with a larger volume has a … pressure?
Lower
Pressure of a gas has what relationship with volume?
Inversely Proportional
What equation shows the relationship between gas and pressure?
If temperature is kept constant
pV = constant
Pressure (Pa) x Volume (m^3) = is always the same
Define Work
Transfer of energy by a force
What happens to the gas inside if you press a piston?
Internal energy increases as you have done work and transferred this energy to the gas
Temperature also increases
