1. Introduction to Circuits

2. Vocabulary Circuit – a path containing mobile charges.
Closed circuit – a circuit that has a complete path for charge to flow.
Conductor – a material that contains easily moveable charges.
Current – the flow of electrical charge.
In a metal wire, current is the flow of negatively charged particles (electrons).
In a battery, your body, or other wet places, current is the flow of both positive and negative charges.
When current flows through a closed circuit, charges flow in a complete loop through the wire and battery.

3. Vocabulary
Fuse – a safety device that melts when current is too high, breaking a circuit.
Insulator – a material that does not contain easily moveable charges.
Open circuit – a circuit that has a break that prevents the flow of current.
Parallel circuit – a circuit that contains two or more branches.
Series circuit – a circuit where moving charges can only follow a single path.
Short circuit – an unwanted electrical connection with very low resistance to current.
Short circuits can produce high levels of current and dangerously high temperatures.

4. Background Knowledge Structure of an atom
Neutron – Neutral particle in the nucleus
Proton – Positively charged particle in the nucleus
Electron – Negatively charged particle in the nucleus
For electricity PROTONS and ELECTRONS are the important players

5. Background Knowledge Opposites attract Similar charges repel
Negatively charged objects are attracted to positively charged objects
Similar charges repel
Positively charged objects repel other positive objects

6. How Electricity Works Let’s start simple, an electrical current
Some atoms hold onto their electrons very tightly
While other atoms give up their electrons very easily
When no outside charge is present electrons just move randomly throughout the object
HOWEVER, when a charge is applied all the electrons start moving in the same direction
This flow of electrons is called a current

7. How Electricity Works A little more complicated, a battery
A battery contains a positive and a negative side
These are separated by an electrolyte to keep them isolated
When the positive and negative sides are connected, the electrons begin to flow FROM NEGATIVE TO POSITIVE
As the electrons move they produce a current that can power electrical devices
When the Anode runs out of electrons the battery “dies”