Unit 10 Electricity (Final Review)

Unit 10 Electricity (Final Review)

Atoms: They are the building blocks of all matter.

Atoms are made up of smaller particles called protons, neutrons and electrons.

Protons have a positive (+1) electric charge

Neutrons are neutral. They have no charge.

Electrons have a negative (-1) electric charge.

When an atom has equal numbers of protons and electrons, the positive charges and negative charges cancel each other. EX. This image has 6 protons and 6 electrons. They cancel each other out so this atom has no charge.

Atoms can gain or lose electrons. When this happens it will give the atom a positive charge or a negative charge. Ex. This atom has two protons and three electrons. The two protons will cancel out two electrons leaving one electron. This electron is -1 electrically charged.

This image the atom has six protons and five electrons. The five protons will cancel out the five electrons leaving one proton left. This atom is positively charge (+1).

Particles with the same charge repel (push away) each other. Two positively charged particles repel each other. Two negatively charged particles will also repel each other.

Particles with opposite charges attract each other.

Static electricity is the build up of electric charge on an object.

Electrostatic discharge is electrons jumping from one object to another.

Electrostatic discharge can be small or big. For example, Lightning is an example of a very strong electrostatic discharge.

Particles in a cloud bump into each other building up an electric charge. Positive charges form at the top of the cloud and negative charges form at the bottom of the cloud. When the difference in charge between the cloud and the ground is great enough there is lightning.

Electric current is when electric charge has a path to follow like in a wire.

A battery is a source of an electric current.

Energy stations change different types of energy like mechanical or nuclear into electrical energy. Energy stations are another source of electrical energy.

Insulators are materials that resist the flow of electric charges.

Conductors are materials that easily allow electric charges to flow through them.

A wire used in an electric device is made up of a conductor and an insulator. The inside of the wire is made of a metal that will easily allow the electric charge to flow. The metal wire is wrapped in an insulator usually rubber or plastic to prevent the wire from getting too hot and causing a fire.

A circuit is a path along which electrical charges can flow. For an electrical device to work, the circuit must form a complete loop (closed circuit)

A closed circuit means there are no breaks in its path. An open circuit means there is a break in its path.

A series circuit has only one path for electric charges to follow. If an part of the path breaks, the circuit is open. The circuit will not work.

A parallel circuit has several different paths for the charges to follow. If one part of the circuit breaks the charges can still flow along other parts.

When there are too many electric devices on one circuit the circuit will overload. This will cause the conductors to get too hot and melt the insulator. To prevent this fuses and circuit breakers are added to a circuit. They will open a circuit if a circuit has too much electric charge in a circuit.

An electric motor is a machine that changes electrical energy into energy of motion.

A magnet is an object that attracts iron and a few other metals.

A magnetic field is the space around the magnet where the force of the magnet acts.

A magnetic pole is the part of the magnet where its magnetic field is the strongest.

A north pole and a south pole are unlike poles. If you place unlike poles of two magnets near each other they will attract (pull together) each other.

Two poles (two north poles or two south poles) that are alike, if you place two magnets near each other then the magnets will repel (push away) from each other

An electromagnet is a device in which electric current produces magnetism.

A generator is a device that converts mechanical energy to electrical energy. It is the opposite of an electromagnet. In an electromagnet we are using an electric current to create a magnetic field. In a generator we are using a magnetic field to create electricity!