IGCSE PHYSICS Notes
THERMAL PHYSICS
IGCSE Physics [Syllabus 2.1] Kinetic Molecular Model
Of Matter
We will cover the topic of thermal physics. Along with that, we will also go
through the molecular model, evaporation, pressure, and its correlation with
temperature and volume. A substance that occupies space is referred to as
matter. Whereas temperature is the average kinetic energy of its particles.
Temperature is essentially the average of all the kinetic energies happening
inside the substance. Gases can be compressed since their particles are spread
out with considerable space. However, solids and liquids cannot be
compressed. Particles' average kinetic energy determines the temperature of
the substance. As energy is removed, particles lose kinetic energy and
molecules start transitioning from a gaseous state to a liquid or solid state
(freezing). When particles get compressed together, they form a solid like in
the case of water freezing inside a freezer.
The pressure of a gas inside a container can be defined as the change in
momentum of the particles that strikes the wall of the container. This leads to
the gas exerting force on the wall. A higher temperature means that the
average kinetic energies of the gas particles are higher. Temperature plays a
big role in this, and another way to look at it is that volume can also affect the
pressure. Evaporation is the process where a liquid changes into a gas below
its boiling point. Boiling, on the other hand, is when a liquid becomes a gas
through heating. As the liquid heats, the particles start to separate out and
eventually turn into a gas.
Particles require a lot of energy to overcome bonds and escape. Therefore, the
ones that escape are the most energetic. As a result, evaporation leads to a
decrease in temperature. This is why humans produce sweat - when it
evaporates, it cools down the skin.
THERMAL PHYSICS
IGCSE Physics [Syllabus 2.1] Kinetic Molecular Model
Of Matter
We will cover the topic of thermal physics. Along with that, we will also go
through the molecular model, evaporation, pressure, and its correlation with
temperature and volume. A substance that occupies space is referred to as
matter. Whereas temperature is the average kinetic energy of its particles.
Temperature is essentially the average of all the kinetic energies happening
inside the substance. Gases can be compressed since their particles are spread
out with considerable space. However, solids and liquids cannot be
compressed. Particles' average kinetic energy determines the temperature of
the substance. As energy is removed, particles lose kinetic energy and
molecules start transitioning from a gaseous state to a liquid or solid state
(freezing). When particles get compressed together, they form a solid like in
the case of water freezing inside a freezer.
The pressure of a gas inside a container can be defined as the change in
momentum of the particles that strikes the wall of the container. This leads to
the gas exerting force on the wall. A higher temperature means that the
average kinetic energies of the gas particles are higher. Temperature plays a
big role in this, and another way to look at it is that volume can also affect the
pressure. Evaporation is the process where a liquid changes into a gas below
its boiling point. Boiling, on the other hand, is when a liquid becomes a gas
through heating. As the liquid heats, the particles start to separate out and
eventually turn into a gas.
Particles require a lot of energy to overcome bonds and escape. Therefore, the
ones that escape are the most energetic. As a result, evaporation leads to a
decrease in temperature. This is why humans produce sweat - when it
evaporates, it cools down the skin.
