FTCE - Science K-6 (Electromagnetic Energy)

Electrical conductivity

a physical property of matter that describes how easily electricity flows through a material.

electrons in electrical conductors

move freely through the material Most metals are good conductors because their electrons are decentralized. A current flows when a voltage is established across a conductor.

electrons in electrical insulators

stay close to their respective nuclei, making them poor electrical conductors. Wood, glass, plastic, and air are electrical insulators.

Magnetism

a force due to electron motion and can be applied to magnetic materials at a distance.

Electricity

the flow of electrons (electric current) or the buildup of charge (static electricity).

Positive protons

are inside the nucleus and cannot escape.

Negative electrons

orbit around the outside of the nucleus of the atom and can escape.

ion

A charged atom

Repelling

Similar, or "like," charges repel. Positive charges repel positive charges, and negative charges repel negative charges. Opposite charges attract one another, negative to positive.

neutral material

equal number of positive and negative charges.

Neutral materials do not react to other neutral charges. However, neutral materials DO attract all charged objects, whether positive or negative

electromagnet

created by allowing electrons to flow through wire coils

temporary magnet or permanent magnet

applies a magnetic force because most of the material's electron spins align

magnetic field.

The area of magnetic influence that surrounds a magnet

Electric circuits

allow for a flow of electrons (electricity) to operate devices.

always have at least three components: 

• a path to conduct electricity 

• a voltage source 

• a resistor 

conducting path

must allow current to flow from one terminal of the voltage source, through the resistor, and back to the other terminal of the voltage source in an unbroken path.

voltage source

the "push" that produces current (the flow of electrons) in a circuit.

resistor

opposes the flow of current in a circuit

current

voltage divided by the resistance

short circuit.

electricity is allowed to flow through a wire with no resistance, the current will be dangerously high

Series circuits

single path and require all elements to be working for electricity to flow.

Parallel circuit

have more than one path; not all elements need to be working for electricity to flow.

Electromagnetic forces

one of the four universal forces and has an infinite range. can both push and pull. stronger than the force of gravity on Earth's surface. exist because electric charges push and pull on each other and because magnetic poles form when charges move