Electricity and Atoms Gr.7 3rd

atoms

Electricity

• Matter is made of tiny building blocks called atoms.

• These consisted of smaller charged particles called protons, neutrons, and electrons.

• The flow of charged particles.

Protons

• positively charged

• when an atom has more protons than electrons

Neutrons

• no electric charges

• if an atom has the same amount of protons and electrons.

Electrons

• Negatively charged

• If an atom has more electrons than protons.

Electrical current

• The flow of electrons around the cuircit.

Electrical Conductors

• All materials contain electrons in materials made of metal.

• The electrons are free to move and carry charge, making them a good conductor.

Electrical Insulators

• The protons hold onto the electrons, so they can’t flow but move in place

Friction and Static electricity

• Electrons can be transferred between insulators by friction when they are rubbed toghether.

Electrostatic Force

• Like magnets, like signs repel while unlike signs attract.

(Electrical Safety)

Grounding

• Grounding wire as an external safety measure.

• Allowing the transfer of excess electrons between charged objects on the ground.

(Electrical Safety)

Lightning Rod

• Created by Benjamin Franklin

• A metal rod on top of the highest part of a building, with a cable connected to the ground.

(Electrical Safety)

Fuse

• Built-in precautions against heating

• Small pieces of metal that melt if the electrical current is too high: needs replacements once used.

(Electrical Safety)

Circuit Breaker

• A reusable safety switch that breaks a circuit when the current is too high.

• It contains a metal that bends and leaves a gap in the circuit.