P3 Particle Model of Matter Flashcards
What is the definition of density? State the relevant equation with units.
- The mass per unit volume of a material
- p = m/v
- Density (kg/m3), Mass (kg), Volume (m3)
State the different states of matter in order (least to most) of density of atoms.
- Least dense: Gas
- Liquid
- Most dense: Solid
Describe the particle arrangement of a solid.
Tightly packed in a regular arrangement. Particles can only vibrate on the spot.
What is always conserved when a substance undergoes a change of state?
Mass
Close together, but with an irregular arrangement. They can flow over each other.
Describe the particle arrangement of a gas.
Separated, with no regular arrangement. Particles can move freely.
How does a change of state differ from a chemical change?
In a change of state, the material can return to having its previous properties if the change is reversed.
What is sublimation?
When a solid changes into a gas without passing through a liquid state.
What is evaporation?
When a liquid changes into a gas state.
What is is the opposite of evaporation?
Condensation, which is when a gas changes into a liquid state.
Explain the processes involved when a bathroom mirror mists up.
- Hot water evaporates to form water vapour
- This water vapour lands on the cooler mirror
- The vapour condenses and returns to liquid state on the mirror’s surface
How does heating affect the energy of a substance?
- Heating transfers energy to the substance
- It increases the energy of the particles that make up the substance
When water boils in an open pan, why does the mass of the pan of water appear to decrease?
Some of the water will evaporate and turn into water vapour. This will leave the pan meaning the mass of the pan will decrease.
The mass of the whole system however remains constant.
What is the internal energy of a substance?
- The energy stored by the particles
- The sum of the total kinetic and
potential energies that make up the total kinetic and potential energies that make up the system
What two things can heating a substance do?
- Raise its temperature
- Change the state of the substance
What three factors determine the temperature change of a system?
- Mass of substance being heated
- Type of material (Specific heat
capacity) - Energy inputted into the system
State the equation used to calculate the temperature change when a substance is heated.
Give appropriate units.
- △Е = m с △θ
- Energy (J), Mass (kg), Specific Heat
Capacity (J/kg/°C), Temperature (°C)
Define specific heat capacity.
The amount of energy needed to increase the temperature of 1kg of a substance by 1°C.
Describe how the internal energy and temperature of a substance changes when a change of state occurs.
- The internal energy of the substance will be increased or decreased
- The temperature of the substance will remain constant
Define specific latent heat.
The amount of energy needed to change the state of 1kg of a substance with no change in temperature.