KO4 Particle model of matter Flashcards
Define density.
The mass per unit of volume.
In words, state the equation that links density, mass and volume.
density = mass ÷ volume
In symbols, state the equation that links density, mass and volume.
ρ = m ÷ V
State the standard units for volume.
Metres cubed (m³)
State the standard units for density.
Kilograms per metre cubed (kg/m³)
Name the three main states of matter.
Solid, liquid and gas
Which state of matter is compressible?
Gas
Explain why solids and liquids are not compressible.
Their particles are all touching.
Describe the arrangement of particles in a solid.
Regular arrangement
Describe the arrangement of particles in a liquid.
Random arrangement
Describe the arrangement of particles in a gas.
Random arrangement
Describe the motion of particles in a solid.
They vibrate without changing position.
Describe the motion of particles in a liquid.
They flow over one another.
Describe the motion of particles in a gas.
They are in constant random motion (in random directions, with a range of speeds).
Which state of matter is the densest: solid, liquid or gas?
Solid
Name the state of matter shown in each diagram.
A - solid
B - gas
C - liquid
Identify the two variables that need to be measured to find the density of an object.
Mass and volume
Describe how the volume of a cube can be established.
Measure the width of the cube with a ruler and then use the equation for the volume of a cube.
Describe how the volume of a sphere can be established.
Measure the diameter of the sphere with a ruler and then use the equation for the volume of a sphere.
Describe how the volume of a liquid can be measured.
With a measuring cylinder.
Convert 1 ml into cm³.
1 ml = 1 cm³
Describe how the mass of a liquid can be established.
Measure the mass of an empty measuring cylinder.
Measure the mass of the same container with the liquid inside it.
Subtract the values.
Name the method that should be used to measure the volume of an irregularly shaped object.
Displacement method
In the context of the displacement method for measuring volume, define displace.
To push out of the way.
A student wants to measure the density of a metal cube. Outline a method to do this. Ensure the method would lead to valid results.
Measure the mass of the cube using a mass balance.
Measure the width, height and length of the cube using a ruler.
Calculate the volume of the cube using the mathematical equation.
Calculate the density by dividing the mass by the volume.
A student wants to measure the density of an irregularly shaped piece of metal. Outline a method to do this. Ensure the method would lead to valid results.
Measure the mass of the metal using a mass balance.
Fill a measuring cylinder with a known volume of water.
Place the metal object into the water and measure the new water volume.
The volume of the object is the new volume of water minus the original volume of water.
Calculate the density by dividing the mass by the volume.
Name the changes of state associated with heating.
Melting, boiling and sublimating (and evaporating)
Name the changes of state associated with cooling.
Condensing and freezing
Name the change of state from solid to liquid.
Melting
Name the change of state from solid to gas.
Sublimation
Name the change of state from liquid to gas.
Boiling
Name the change of state from gas to liquid.
Condensing
Name the change of state from liquid to solid.
Freezing
Explain the difference between boiling and evaporation.
Boiling happens at the boiling point when all of the substance changes state.
Evaporation happens below the boiling point.
Explain why mass is conserved during a change of state.
Particles are not lost or gained.
Define physical change.
When a substance changes state, but does not change what substance it is.
Are physical changes reversible?
Yes
Define chemical change.
When a substance reacts with something and changes what substance it is.
Are chemical changes reversible?
No
Define internal energy.
Energy that is stored inside an object by the particles.
Describe the relationship between internal energy, total kinetic energy of the particles and total potential energy of the particles.
internal energy = total kinetic energy of the particles + total potential energy of the particles
State the part of the internal energy that changes if the temperature of an object changes.
The total kinetic energy of the particles
Describe the relationship between the total kinetic energy of the particles and temperature of the substance.
The greater the total kinetic energy of the particles, the greater the temperature.
State the effect on the state of a system if the total kinetic energy of particles changes.
Nothing, the state stays the same.
State the part of the internal energy that changes if the state of a system changes.
The total potential energy of the particles
State the effect on the state of a system if the total potential energy of particles changes.
The state changes.
State the two things that can occur when a substance is heated.
The temperature can increase or the state can change.
Describe the change in temperature of a substance during a change of state.
The temperature remains constant.
State the two things that can occur when a substance is cooled.
The temperature can decrease or the state can change.
In which state of matter is the internal energy highest?
Gas
In words, state the equation that links the energy needed for a change of state, mass and specific latent heat.
energy needed for a change of state = mass × specific latent heat
In symbols, state the equation that links the energy needed for a change of state, mass and specific latent heat.
E = m × L
State the standard units for specific latent heat.
Joules per kilogram (J/kg)
Define latent heat.
The total energy needed to change the state of a system (with no change in temperature).
Define specific latent heat.
The energy needed to change the state of a system per kilogram (with no change in temperature).
Define specific latent heat of fusion.
The energy needed to change the state of a system from solid to liquid, per kilogram.
Define specific latent heat of vaporisation.
The energy needed to change the state of a system from liquid to gas, per kilogram.
Which letter on the heating curve represents the section that shows melting?
B
Which letter on the heating curve represents the section that shows boiling?
D
Which letter on the heating curve represents the section that shows a solid increasing in temperature?
A
Which letter on the heating curve represents the section that shows a liquid increasing in temperature?
C
Which letter on the heating curve represents the section that shows melting?
E
Which letter on the cooling curve represents the section that shows condensing?
B
Which letter on the cooling curve represents the section that shows freezing?
D
Which letter on the cooling curve represents the section that shows a solid decreasing in temperature?
E
Which letter on the cooling curve represents the section that shows a liquid decreasing in temperature?
C
Which letter on the cooling curve represents the section that shows a gas decreasing in temperature?
A
State the effect on the temperature of a gas if the average kinetic energy of the particles increases.
The temperature increases.
State the effect on the temperature of a gas if the average kinetic energy of the particles decreases.
The temperature decreases.
Describe the cause of gas pressure.
The collisions of the gas particles with the walls of the container.
State the effect on the pressure of a gas if the temperature of the gas is increased (with the volume constant).
The pressure increases.
State the effect on the pressure of a gas if the temperature of gas is decreased (with the volume constant).
The pressure decreases.
State the effect on the volume of a gas if the pressure of the gas is increased (with the temperature constant).
The volume decreases.
State the effect on the volume of a gas if the pressure of the gas is decreased (with the temperature constant).
The volume increases.
State the effect on the pressure of a gas if the volume of the gas is decreased (with the temperature constant).
The pressure increases.
State the effect on the pressure of a gas if the volume of the gas is increased (with the temperature constant).
The pressure decreases.
Explain why increasing the volume in which a gas is contained decreases the pressure.
The collisions of the gas particles with the walls of the container are spread over a larger area.
In words, state the equation that links pressure and volume.
pressure × volume = constant
In symbols, state the equation that links pressure and volume.
p × V = constant
State the standard units for pressure.
Pascals (Pa)
State the standard units for volume.
Metres cubed (m³)
Define doing work on a gas.
Transferring energy to the gas.
State the effect on the internal energy of a gas if work is done on it.
The internal energy increases.
State the effect on the temperature of a gas if work is done on it.
The temperature increases.
State the effect on the motion of particles in a gas if work is done on it.
The particles move faster.
Describe how work can be done on a gas.
By applying a force to the gas, e.g. with a bicycle pump.
