Define internal energy .

Internal energy is the total energy stored inside a system by the particles that make up the system due to their motion and positions .

What are the two energy stores that make up a substance's internal energy ?

The kinetic store (due to the random motion or vibration of particles) and the potential store (due to their position relative to each other).

What effect does heating a system have on its internal energy ?

Heating a system increases its internal energy.

How is temperature related to the kinetic energy of the molecules in a substance?

Temperature is related to the average kinetic energy of the molecules. The higher the temperature, the higher the kinetic energy of the molecules, and vice versa.

What two things can an increase in internal energy from heating cause?

It can cause the temperature of the system to increase, or produce a change of state (solid to liquid, or liquid to gas).

When a substance changes state, the potential energy of the molecules increases, allowing them to overcome the intermolecular forces of attraction, while the ______ energy remains the same.

When a substance changes state, the potential energy of the molecules increases, allowing them to overcome the intermolecular forces of attraction, while the kinetic energy remains the same.

True or False? When a substance changes state, its temperature stays the same even though it is still being heated.

True. The energy transferred stops increasing the kinetic energy of the molecules and instead increases their potential energy, overcoming the intermolecular forces of attraction, so the temperature remains constant.

Define specific heat capacity .

Specific heat capacity is the amount of energy required to raise the temperature of 1 kg of a substance by 1 °C.

What three factors does the increase in temperature of a substance depend on?

The mass of the substance heated, the type of material , and the energy input to the system.

If a substance has a low specific heat capacity, how quickly does it heat up and cool down?

It heats up and cools down quickly , as it takes less energy to change its temperature.

Good electrical conductors, such as copper and lead, tend to have a ______ specific heat capacity.

Good electrical conductors, such as copper and lead, tend to have a low specific heat capacity.

Good electrical conductors, such as copper and lead, are excellent conductors of heat due to their ______ specific heat capacity.

Good electrical conductors, such as copper and lead, are excellent conductors of heat due to their low specific heat capacity.

True or False? Specific heat capacity is mainly used to describe gases.

False. Specific heat capacity is mainly used for liquids and solids .

Latent heat is the energy needed for a substance to change state.

What happens to the temperature of a substance while it is changing state?

The temperature remains constant , despite energy still being transferred to or away from the substance.

Why does the temperature remain constant during a change of state?

Because the energy is being used to overcome the intermolecular forces of attraction between the molecules, instead of increasing their kinetic energy (and hence the temperature).

Name the two types of latent heat .

Latent heat of fusion and latent heat of vaporisation .

To change state from a liquid to a gas, the molecules need to gain enough energy to overcome the ______ forces of attraction holding them close together.

To change state from a liquid to a gas, the molecules need to gain enough energy to overcome the intermolecular forces of attraction holding them close together.

True or False? Molecules in a liquid are more tightly bound together than molecules in a solid.

False. The specific latent heat of vaporisation is greater than the specific latent heat of fusion, as more energy is needed to fully separate particles into a gas than to allow them to move past each other as a liquid.

Define specific latent heat .

Specific latent heat is the amount of energy required to change the state of 1 kg of a substance with no change in temperature.

Define the specific latent heat of fusion .

The specific latent heat of fusion is the energy required to convert 1 kg of a substance between a solid and a liquid state with no change in temperature.

Define the specific latent heat of vaporisation .

The specific latent heat of vaporisation is the energy required to convert 1 kg between a liquid and a gaseous state with no change in temperature.

Does the specific latent heat of vaporisation apply only to vaporising a liquid, or also to condensing a gas?

It applies to both : vaporising a liquid or condensing a gas, occurring at the same temperature (the boiling point).

Evaporating 1 kg of water requires roughly ______ times more energy than melting the same mass of ice.

Evaporating 1 kg of water requires roughly seven times more energy than melting the same mass of ice.

True or False? The specific latent heat of fusion of water is greater than its specific latent heat of vaporisation.

False. Water's specific latent heat of fusion is 330 kJ/kg, while its specific latent heat of vaporisation is 2.26 MJ/kg, which is greater.

What two things do heating and cooling graphs summarise?

How the temperature of a substance changes when energy is transferred to or away from it, and where changes of state occur.

On a heating graph, why does the temperature stop increasing when a solid reaches its melting point?

The energy transferred is now used to overcome the intermolecular forces of attraction holding the particles in their solid structure, rather than increasing their temperature. This is melting .

Name the process by which a gas turns into a liquid, and the process by which a liquid turns into a solid, during cooling.

Condensation (gas to liquid) and freezing (liquid to solid).

When energy is transferred away from a liquid during cooling, the temperature decreases until it reaches the substance's ______ point, at which point freezing begins and the temperature stops decreasing.

When energy is transferred away from a liquid during cooling, the temperature decreases until it reaches the substance's freezing point, at which point freezing begins and the temperature stops decreasing.

On the heating graph, what is happening to a substance's particles from the origin to point A (before melting begins)?

The energy transferred to the substance is increasing the kinetic energy of the particles while it is a solid , so the temperature rises.

On the heating graph, what is happening to a substance's particles from point D to point E (after boiling is complete)?

The energy transferred is further increasing the kinetic energy of the particles while the substance is a gas , so the temperature continues to rise.

True or False? The temperature of a substance stays constant while it is entirely in the liquid state during heating.

False. The temperature increases while the substance is entirely liquid; it only stays constant during a change of state (melting or boiling).

What is the key difference between specific heat capacity and specific latent heat , in terms of the substance's state and temperature?

Specific heat capacity relates to a substance staying in the same state but reaching a different temperature . Specific latent heat relates to a substance changing state while staying at the same temperature .

Give an example of a situation described by specific heat capacity .

A liquid being heated from 5 °C to 20 °C ( same state , different temperature ).

Give an example of a situation described by specific latent heat .

A liquid evaporating into a gas ( same temperature , change of state ).

Specific heat capacity refers to a substance remaining in the ______ state but reaching a different temperature.

Specific heat capacity refers to a substance remaining in the same state but reaching a different temperature.

True or False? Specific latent heat describes a change in temperature.

False. Specific latent heat describes a change of state with no change in temperature .

Is boiling water an example of specific heat capacity or specific latent heat ? Explain your answer.

Specific latent heat , because the water is changing state (liquid to gas) while its temperature remains constant.

GCSEPhysicsAQAFlashcardsParticle Model of MatterInternal Energy & Energy Transfers

Internal Energy & Energy Transfers (AQA GCSE Physics): Flashcards

Exam code: 8463

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Define internal energy.

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Cards in this collection (40)

Define internal energy.
Internal energy is the total energy stored inside a system by the particles that make up the system due to their motion and positions.
What are the two energy stores that make up a substance's internal energy?
The kinetic store (due to the random motion or vibration of particles) and the potential store (due to their position relative to each other).
What effect does heating a system have on its internal energy?
Heating a system increases its internal energy.
How is temperature related to the kinetic energy of the molecules in a substance?
Temperature is related to the average kinetic energy of the molecules. The higher the temperature, the higher the kinetic energy of the molecules, and vice versa.
What two things can an increase in internal energy from heating cause?
It can cause the temperature of the system to increase, or produce a change of state (solid to liquid, or liquid to gas).
When a substance changes state, the potential energy of the molecules increases, allowing them to overcome the intermolecular forces of attraction, while the ______ energy remains the same.
When a substance changes state, the potential energy of the molecules increases, allowing them to overcome the intermolecular forces of attraction, while the kinetic energy remains the same.
True or False?
When a substance changes state, its temperature stays the same even though it is still being heated.
True.
The energy transferred stops increasing the kinetic energy of the molecules and instead increases their potential energy, overcoming the intermolecular forces of attraction, so the temperature remains constant.
Define specific heat capacity.
Specific heat capacity is the amount of energy required to raise the temperature of 1 kg of a substance by 1 °C.
State the equation linking change in energy, mass, specific heat capacity and change in temperature, including the units of each symbol.
$Δ E = m c Δ θ$
Where ΔE = change in energy (J), m = mass (kg), c = specific heat capacity (J/kg °C), and Δθ = change in temperature (°C).
What three factors does the increase in temperature of a substance depend on?
The mass of the substance heated, the type of material, and the energy input to the system.
If a substance has a low specific heat capacity, how quickly does it heat up and cool down?
It heats up and cools down quickly, as it takes less energy to change its temperature.
Good electrical conductors, such as copper and lead, tend to have a ______ specific heat capacity.
Good electrical conductors, such as copper and lead, tend to have a low specific heat capacity.
Good electrical conductors, such as copper and lead, are excellent conductors of heat due to their ______ specific heat capacity.
Good electrical conductors, such as copper and lead, are excellent conductors of heat due to their low specific heat capacity.
True or False?
Specific heat capacity is mainly used to describe gases.
False.
Specific heat capacity is mainly used for liquids and solids.
Define latent heat.
Latent heat is the energy needed for a substance to change state.
What happens to the temperature of a substance while it is changing state?
The temperature remains constant, despite energy still being transferred to or away from the substance.
Why does the temperature remain constant during a change of state?
Because the energy is being used to overcome the intermolecular forces of attraction between the molecules, instead of increasing their kinetic energy (and hence the temperature).
Name the two types of latent heat.
Latent heat of fusion and latent heat of vaporisation.
To change state from a liquid to a gas, the molecules need to gain enough energy to overcome the ______ forces of attraction holding them close together.
To change state from a liquid to a gas, the molecules need to gain enough energy to overcome the intermolecular forces of attraction holding them close together.
True or False?
Molecules in a liquid are more tightly bound together than molecules in a solid.
False.
The specific latent heat of vaporisation is greater than the specific latent heat of fusion, as more energy is needed to fully separate particles into a gas than to allow them to move past each other as a liquid.
Define specific latent heat.
Specific latent heat is the amount of energy required to change the state of 1 kg of a substance with no change in temperature.
Define the specific latent heat of fusion.
The specific latent heat of fusion is the energy required to convert 1 kg of a substance between a solid and a liquid state with no change in temperature.
Define the specific latent heat of vaporisation.
The specific latent heat of vaporisation is the energy required to convert 1 kg between a liquid and a gaseous state with no change in temperature.
State the equation linking thermal energy, mass and specific latent heat, including the units of each symbol.
$E = m L$
Where E = thermal energy required for a change in state (J), m = mass (kg), and L = specific latent heat (J/kg).
Does the specific latent heat of vaporisation apply only to vaporising a liquid, or also to condensing a gas?
It applies to both: vaporising a liquid or condensing a gas, occurring at the same temperature (the boiling point).
Evaporating 1 kg of water requires roughly ______ times more energy than melting the same mass of ice.
Evaporating 1 kg of water requires roughly seven times more energy than melting the same mass of ice.
True or False?
The specific latent heat of fusion of water is greater than its specific latent heat of vaporisation.
False.
Water's specific latent heat of fusion is 330 kJ/kg, while its specific latent heat of vaporisation is 2.26 MJ/kg, which is greater.
What two things do heating and cooling graphs summarise?
How the temperature of a substance changes when energy is transferred to or away from it, and where changes of state occur.
On a heating graph, why does the temperature stop increasing when a solid reaches its melting point?
The energy transferred is now used to overcome the intermolecular forces of attraction holding the particles in their solid structure, rather than increasing their temperature. This is melting.
Name the process by which a gas turns into a liquid, and the process by which a liquid turns into a solid, during cooling.
Condensation (gas to liquid) and freezing (liquid to solid).
When energy is transferred away from a liquid during cooling, the temperature decreases until it reaches the substance's ______ point, at which point freezing begins and the temperature stops decreasing.
When energy is transferred away from a liquid during cooling, the temperature decreases until it reaches the substance's freezing point, at which point freezing begins and the temperature stops decreasing.
On the heating graph, what is happening to a substance's particles from the origin to point A (before melting begins)?
The energy transferred to the substance is increasing the kinetic energy of the particles while it is a solid, so the temperature rises.
On the heating graph, what is happening to a substance's particles from point D to point E (after boiling is complete)?
The energy transferred is further increasing the kinetic energy of the particles while the substance is a gas, so the temperature continues to rise.
True or False?
The temperature of a substance stays constant while it is entirely in the liquid state during heating.
False.
The temperature increases while the substance is entirely liquid; it only stays constant during a change of state (melting or boiling).
What is the key difference between specific heat capacity and specific latent heat, in terms of the substance's state and temperature?
Specific heat capacity relates to a substance staying in the same state but reaching a different temperature. Specific latent heat relates to a substance changing state while staying at the same temperature.
Give an example of a situation described by specific heat capacity.
A liquid being heated from 5 °C to 20 °C (same state, different temperature).
Give an example of a situation described by specific latent heat.
A liquid evaporating into a gas (same temperature, change of state).
Specific heat capacity refers to a substance remaining in the ______ state but reaching a different temperature.
Specific heat capacity refers to a substance remaining in the same state but reaching a different temperature.
True or False?
Specific latent heat describes a change in temperature.
False.
Specific latent heat describes a change of state with no change in temperature.
Is boiling water an example of specific heat capacity or specific latent heat? Explain your answer.
Specific latent heat, because the water is changing state (liquid to gas) while its temperature remains constant.

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