Unit 3 - Particle model of Matter Flashcards
Equation for Density
Density = Mass / Volume
ρ =m / V
Units for:
- Density,
- Mass &
- Volume
- kg/m^3 or g/cm^3
- kg or g
- m^3 or cm^3
What can the particle model explain?
- The different states of Matter
- Differences in Denisty
What are the steps to calculating the density of regular objects?
- Measure the mass of the object using a balance or scales.
2.Fill a measuring cylinder with enough water to submerse the object.
- Take a reading of the volume of water in the Measuring Cylinder.
- Place the object in the Measuring Cylinder and ensure it is submersed.
- Take a reading of the volume of water + object in the Measuring Cylinder.
- Subtract the volume of water from the volume of water + object to find the volume of the object.
7.Use the equation ρ=mV
to calculate the density of the irregular object.
Density formula
(Mass as Subject)
Mass = Density x Volume
Density Formula
(Volume as Subject)
Volume = Mass / Density
What is internal energy?
The total kinetic energy and potential energy of all
the particles (atoms and molecules) that make up a system.
Changes of state are…
Physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.
Equation for SHC
Change in Thermal energy = Mass x Specific Heat Capacity x Change in Temperature
∆ E = m c ∆ θ
Equation for SHC
(Change in Temp. as Subject)
Change in Temp = Thermal energy / (Mass x SHC)
Equation for SHC
(SHC as Subject)
SHC = Change in Temp. / (Mass x Thermal energy)
Equation for SHC
(Mass as Subject)
Mass = Change in Temp. / (Thermal energy x SHC)
Units for:
- SHC,
- Mass,
- Change in Temp. &
- Thermal Energy
- J/kg°C
- kg
- °C
- J
Why doesn’t the internal energy supplied increase the temperature of a substance about to change state?
Its being used to break bonds between atoms
What is SHC?
The amount of energy a substance needs to raise the temperature of 1kg of this substance by 1°C
What is SLH
The amount of energy a substance needs to change the state of 1kg of this substance by 1°C, with no change in temperature
Equation for SLH
Energy needed for a change in state = Mass x SLH
Units for:
- SLH,
- Mass
- Energy
- J/kg
- kg
- J
What is the specific latent heat of fusion?
Change of state from solid to liquid or liquid to solid
What is the specific latent heat of vaporisation?
Change of state from liquid to gas or gas (vapour) to liquid.
The molecules of a gas are in constant random motion…
The temperature of the gas is related to the average kinetic energy of the molecules.
How is the temprature of gas related to its pressure?
The particles with higher kinetic energy stores move faster, colliding harder and more often with each other and the walls of the container (increasing pressure in a fixed container).
Temperature and Pressure are ____ Proportional
Directly
Equation for Pressure
Pressure = Force / Area
P = F / A
Pressure and Force are ____ Proportional
Directly
Pressure and Area are ____ Proportional
Inversely
Units for:
- Pressure
- Force
- Area
- Pa (pascals)
- N (newtons)
- m^2 (metres sqaured)
Equation for Constant
Constant = Pressure x Volume
pV = Constant
How does doing work on an enclosed gas leads to an increase?
The increase in the internal energy of the gas (as kinetic energy of the particles) means that the temperature must increase.
