General Outcome #1: Investigate technologies that transfer and control electricity.

ELECTRICITY – TOPIC 1: ELECTRIC CHARGES There are two general types of electricity: Static Electricity- the build-up of an electrical charge (electrons) on an object -the electrical charge will move when it comes into contact with a object that has a different charge then it -better to call it an Unbalanced Charge 2. Current Electricity- the continuous movement of charged particles (electrons) along a pathway -electricity that moves in in a circuit

Electric Forces: when objects that have a charge attract or repel each other -an object with an electrical charge wants to have the same charge with objects around them, so they may pick up extra electrons or may lose extra electrons to become balanced -when this happens, an Electrical Discharge takes place –gaining or removing of an electric charge e.g. shock, lightning

2. Positive Charge –a shortage of electrons (more protons) 3 Types of Charges (REMEMBER: electrons are free to move, protons are stuck in the nucleus) 1. Neutral Charge –equal positive and negative charges 2. Positive Charge –a shortage of electrons (more protons) 3. Negative Charge –having more electrons than protons

3. Charged objects attract neutral (uncharged) objects. Three Laws of Electric Charges 1. Opposite charges attract each other. (something with a positive charge can neutralize something with a negative charge) 2. Similar charges repel each other. (because they have the same charge, they can’t help each other out) 3. Charged objects attract neutral (uncharged) objects. (because they want to be balanced, the neutral object will try to accept a charge from the charged object)

Can I distinguish between static and current electricity, and identify examples of each?

Conductors, Insulators and Semi-Conductors Insulators are materials that do not allow electric charges to move freely on or through them.

Semi-Conductors allow electrons to move but not freely. Anything that's computerized or uses radio waves depends on semiconductors. Carbon, silicon and germanium have a unique property in their electron structure -- each has four electrons in its outer orbital. This allows them to form nice crystals. (perfect covalent bonds with four neighbouring atoms), creating a lattice.

In a silicon lattice, all silicon atoms bond perfectly to four neighbours, leaving no free electrons to conduct electric current. This makes a silicon crystal an insulator rather than a conductor. BUT... You can change the behaviour of silicon and turn it into a conductor by doping it. In doping, you mix a small amount of an impurity such as phosphorus, arsenic, boron or gallium into the silicon crystal which allows an electric current to flow through the silicon.

Conductors are materials that allow electric charges to move freely. Metals tend to be good conductors of electricity because they usually have "free electrons" that can move easily between atoms. Copper wire spools

Superconductors are materials that offer little if any resistance to the flow of electric charges. Superconductivity is a phenomenon observed in several metals and ceramic materials. When these materials are cooled to temperatures ranging from near absolute zero (0 degrees Kelvin, -273 degrees Celsius) they have no electrical resistance - electrons can travel through them freely. Superconductors can carry large amounts of electrical current for long periods of time without losing energy as heat. This property has implications for electrical power transmission (if transmission lines can be made of superconducting ceramics) and for electrical storage devices.

Meissner Effect . A superconductive disk on the bottom, cooled by liquid nitrogen, causes the magnet above to levitate. The floating magnet induces a current, and therefore a magnetic field, in the superconductor, and the two magnetic fields repel to levitate the magnet.

Maglev Trains http://videos.howstuffworks.com/discovery/29341-extreme-engineering-maglev-train-video.htm

Can I identify electrical conductors and insulators?