How thermal energy is transferred

Thermal energy is transferred by:

1. Convection


2. Conduction


3. Radiation

Convection can only happen in liquids and gases. Solids can not convect! Convection is the transfer of thermal energy in a fluid/gas from place to place

Conduction is transferring energy through matter with a direct contact of particles. Particles are always moving(according to the kinetic theroy), and the transfer of the thermal energy happens when these always moving particles collide with each other.

Radiation is the transfer of energy from electromagnetic waves. Radiation can pass through solids, liquids, and gases. It also does not need matter, or direct contact to travel. When radiation hits a material some of the energy is absorbed, reflected, or transmitted through the atmosphere. Light colored materials reflect more energy than dark ones. *When a material absorbs radiant energy, its thermal energy increases.

First Law of Thermodynamics: says the thermal energy of a system= the work done on the system+the heat added to the system. Basically it says that energy can be transformed, or converted into something else, but it can never be created or destroyed.

Second Law of Thermodynamics: says that is it impossible for heat to flow from a cool object to a warmer object unless work is done. Ex) An ice cube can turn to ice without work being done, but water can't turn into an ice cube unless work is done.

How thermal energy move throughout a system

Thermal energy moves throughout a system by a convection current. The difference in densities between warmer and cooler fluid or air cause the current to happen.
Ex.1) Warm water at the bottom of a pan is less dense than the colder water at the top, then the warm water is pushed to the top, and the cold to the bottom. This keeps happening, making the current.
Ex.2) Currents happen in the atmosphere. Warm air from the equator moves toward the poles, while the poles cold air moves toward the equator.

The differences in the four states of matter, and how the motion of particles in a material changes when material changes state

The four states;
Solid matters' particles are tightly held together, and in a difinate shape. Liquid particles are held together losely and can form different shapes. Gas particles are going seperate ways, and they arent connected. And plasma particles are either positive+, or negitive-, and they're just floating around.

How they change;
When a solid changes to a liquid its called melting, the particles move faster. Also, to change 1kg of a solid to a liquid 1degree is called heat of fusion.

And when a liquid changes to a solid its called freezing. To freeze something you have to remove the energy, when you decrease the liquids temperature, you decrease the average kinetic energy, so the particles move slower. Eventually the forces between the particles are strong enough to take a definate form.

When a liquid changes to a gas it's called vaporization, as the temperature of the liquid increases, the particles move faster. Eventually the forces between the particles become too weak, and can't hold together. Vaporization can happen at the surface of the liquid, or within the liquid.

Condensation is when a gas turns to a liquid.. The particles lose heat energy, but the forces between the particles get stronger and stay together losely.

When a gas turns into plasma, its called ionization. The particles move faster, and turn into positive and negitive particles and "float" in different directions not connected..

And when a plasma turns into a gas its called deionization.

Relationship between temperature, heat & thermal

Temperature is a measure of the average kinetic every of the particles in the sample of matter. All the particles in a matter are moving at different speeds. The faster the average movement of the particles = a higher average temperature.

Heat is the energy that flows from something with a higher temperature to something with a lower temperature. It is also measured in Joules(J)

Thermal Energy is the total energy of the particles that make up a material. To find thermal energy you add all the sums of energy(potential&kinetic energy) to find thermal energy. It also depends on:

1.Mass

2.Type of substance

3.Temperature

So the faster an object moves, the more kinetic energy it has.

Ex) a ball rolling

a ball sitting

ALWAYS from a WARMER object to a COOLER object

And a thermal insulator is something that doesn't allow heat to flow through it easily. Such as a thermos bottle to keep your hot drink warm. The thermos keeps the warm air inside instead of escaping.

So, they are all different but; temperature is the average measure of the energy. Thermal energy is thetotal energy of the particles, and heat is the flow of the energy from something with a higher temperature to something with a lower temperature.