Unit 1 Topic 1 - Heating processes

Solid particle model

Particles are arranged in a rigid lattice or array; they have strong bonds which ensure they don’t move away, remaining vibrating in a fixed position.

Liquid particle model

The particles have a medium density, move over each other with medium kinetic energy, have medium forces of attraction and take the shape of any given vessel.

Gas particle model

The particles have low density, move around freely with high kinetic energy, have low forces of attraction and can fill the space of any vessel.

Plasma

A highly random form of matter that can be thought of as a combination of positive ions and electrons as well as intact atoms and molecules, all moving rapidly and chaotically.

Thermal energy

The internal energy of an object due to the kinetic energy of its atoms and molecules vibrating.

Temperature

The average kinetic energy of the particles in a substance.

Kinetic energy

The energy an object has because of its motion.

Heat

The transferred energy from one object to another due to a temperature difference.

Internal energy

The total potential energy and kinetic energy of the particles in a system.

Conduction

The process by which the particles in a solid collide with each other to transfer energy evenly throughout the solid or between the solid and another object.

Convection

The movement caused in a liquid or gas by the tendency of hotter, less dense particles to rise and colder, more dense particles to sink under the influence of gravity, consequently resulting in a transfer of heat.

Radiation

Energy transferred via electromagnetic waves or moving subatomic particles, described as ionising or non-ionising. When coming into contact with an object, the molecules vibrate and begin to move faster.

Thermal insulator

An object that slows or stops the movement of heat, and is very bad at conducting heat.

Thermal conductor

An object that is able to absorb heat/thermal energy very well due to its properties.

Specific heat capacity

The amount of energy, measured in joules, required to raise the temperature of 1kg of a substance by one degree (or 1K).

Tk = Tc + 273

The standard conversion from kelvin to Celsius.

Absolute zero

The point at which all particles have absolutely no kinetic energy whatsoever. This is denoted by 0K or -273oC.

Energy input/output formula

Q=mc∆t, where Q is energy input/output, m is the mass, c is the specific heat capacity, and delta t is the net change in temperature.

Law of conservation of energy

States that energy cannot be created or destroyed; Qgained = Qlost.

Zeroth law of thermodynamics

If object A is in equilibrium with object B, and object B is in equilibrium with object C, then object A and C are in equilibrium.

First law of thermodynamics

Energy cannot be created or destroyed, it can only be transferred or transformed.

Second law of thermodynamics

The universe's total entropy will always increase over time. Heat will always flow spontaneously from hotter objects to colder objects.

Latent heat

The process where the temperature of a substance remains constant during a change of state because the potential energy is increasing while the kinetic energy remains constant.

Specific latent heat fusion

The energy required to change 1kg of a substance from solid to liquid or liquid to solid without a change in temperature.

Specific latent heat vaporisation

The energy required to change 1kg of a substance from liquid to gas or gas to liquid without a change in temperature.

SLH formula

Q = mL, where Q is the amount of energy required, m is the mass of the object and L is the specific latent heat.