Energy transfer in electrical systems, static electricity, chemical reactions, and gas pressure (Review Notes)

Vocabulary flashcards covering key terms from the lecture notes on electricity, static electricity, chemical reactions, and gas pressure.

Short circuit

An electric circuit path that allows current to flow along an unintended route, offering the least resistance and potentially causing overheating or fires.

Magnetic field

The region of force surrounding a permanent magnet or a moving charged particle; can be visualized around a conductor with iron filings.

Electric current

The flow of electric charges through a circuit; transfers energy from the source to components and can cause heating.

Filament

The resistance wire inside a light bulb (usually tungsten); high resistance causes it to heat up and emit light.

Resistor

A component that opposes the flow of current and converts electrical energy into heat to control current.

Circuit diagram

A simplified drawing of an electric circuit using standard symbols to represent components.

Cell

A chemical system that stores electrical potential energy and acts as a source of energy in a circuit; has positive and negative terminals.

Battery

Two or more cells connected together to store electrical potential energy.

Conducting wires

Materials through which electrons can flow, usually metals like copper.

Switch

A device that opens or closes a circuit to stop or start the flow of electric charge.

Open circuit

A circuit with a gap that prevents current from flowing.

Closed circuit

A circuit with a complete path that allows current to flow.

Energy transfer in electrical systems

Process where electrical energy is converted to other forms (light, heat, sound) by circuit components.

Bulb

An incandescent lamp that produces light when current passes through its filament.

A cell vs a battery

A cell is a single chemical source of energy; a battery is a combination of two or more cells.

Conducting wires (definition)

Materials that allow electron flow; metals are good conductors.

Electric charge

A property of particles that can be positive or negative (protons are positive, electrons are negative).

Static electricity

Build-up of electric charges on the surface of an insulator with little or no continuous current.

Electric spark

A brief flash of light produced by the discharge of static electricity.

Friction (charging by)

Rubbing materials transfers electrons, causing one material to become negatively charged and the other positively charged.

Attraction and repulsion of charges

Opposite charges attract; like charges repel.

Chemical reaction

A process where substances react to form new substances with different properties.

Reactants

Substances that participate in a chemical reaction (on the left side of a chemical equation).

Products

Substances formed from a chemical reaction (on the right side of a chemical equation).

Chemical bonds

Forces that hold atoms together; bonds break and form as reactions occur.

Chemical equation

A symbolic representation of a chemical reaction showing reactants on the left, products on the right, with an arrow indicating direction.

Rusting

Iron reacts with oxygen (and moisture) to form iron oxide (rust).

Fermentation

Yeast converts sugars into alcohol and carbon dioxide; occurs slowly.

Neutralisation

An acid-base reaction that produces a salt and water (e.g., HCl + Mg(OH)2 → MgCl2 + H2O).

Combustion

Burning of fuels (e.g., octane with oxygen to form carbon dioxide and water).

Signs of chemical reaction

Color change, gas bubbles, heat or cold, and smell indicate a reaction is occurring.

Gas pressure

The force exerted by gas particles when they collide with the walls of their container.

Tyre/balloon pressure

Increasing the amount of gas or its temperature raises collisions and thus pressure; too little gas leads to flat tyres or floppy balloons.