Teacher Imarlys Cajigas 5th grade Science Electricity Teacher Imarlys Cajigas 5th grade Science

Introduction to Electricity You use electricity every day, but you don’t know what it is? To understand electricity you have to think about atoms. Protons have positive charge. Electrons have negative charge and move outside of the nucleus. Neutrons have no charge. http://www.youtube.com/watch?v=d3YR8e_iHlk

Electricity Electricity or electric energy, is a form of energy produced by moving electrons.

Electricity can be change to other forms of energy. Light Motion or Mechanical Energy Heat energy Sound energy

Electricity and Magnetism An electromagnet is a magnet made by coiling a wire around a piece of iron and running electricity through a wire. While the electricity flows through the wire, it has a magnetic field around it. Each extra turn of the wire makes the field even stronger.

Uses of Electromagnets Electromagnets can be turned on and off. They are used to hold heavy fire doors open, they are used on cranes in steel recycling centers, can be used to lift metal objects off ships. A small electromagnet is used on doorbells.

Electricity and Magnetism You have seen that electricity can produce magnetism but it also works the other way around- a magnet can produce electricity. 1-In an energy station, a coil of wire turns inside the magnetic field of a huge magnet. 2-When the wires cut across the magnetic field, electricity flows through the wires. 3-Electricity travels from the station over a series of wires to schools, homes, and offices.

How an electric motor works? A motor contains a coil of wire that can spin inside the magnetic field of a permanent magnet. When the motor is switched on, electricity produces a magnetic field in the coil of wire (electromagnet). The poles of the electromagnet are attracted and repelled by the poles of the permanent marker causing it to spin. The motion of the spinning coil turn the motor.

Lesson Review Why is electricity sometimes describes as a flow of electrons? How do neutrons affect an electric charge? How can you make an electromagnet stronger? Which part of an atom is involved in electricity? Electricity is a form of _________. Electricity can be changed into __________, __________, __________, and _________ energy.

Lesson 2: What are Static and Current Electricity?

Static Electricity Most objects have no charge, they have equal number of protons and electrons. But when one object rubs against another, electrons move from atoms of one object to atoms of another object. The object becomes either positively or negatively charged. The build up of charges is called static electricity.

Static Electricity Opposite charges attract each other. Charged objects also attract neutral objects. The shock you feel sometimes when you touch metal objects is caused by electrons moving. The sparks are static discharge.

Lightning Lightning is also a static discharge. Scientists hypothesize that collisions between water droplets in a cloud cause the drops to become charged. Negative charges collect at the bottom of the cloud and positive charges collect at the top of the cloud. When electrons move form one cloud to another or from one cloud to the ground you see the lightning. The lightning heats the air, causing it to expand. As cooler air move to fill the empty spaces, you hear thunder.

Lightning Formation http://www.youtube.com/watch?v=jM8h60S1GsM

Current Electricity For electricity to be a useful source of energy, it must be a steady flow of charges. If electrons have a path to follow, the charges will move in a steady flow, instead of building up a static charge. This flow of charges is called an electric current. Electricity that flows this way is called current electricity

Current Electricity The electrical pressure is measured in volts. Batteries have labels that show the number of volts they supply. The rate at which electric charges flow is measured in amps. The amount of electrical energy a device uses each second is measured in watts. One kilowatt is equal to 1,000 watts.

Conductors and Insulators A material through which electricity moves well is a conductor. Most metals are conductors. The electrons of metals are held loosely by the atoms. An insulator is a material that conducts electricity poorly. Wood, glass, and rubber are insulators.

Lesson Review What kind of electricity does a TV use? What kinds of energy does the TV produce from this electricity? What is the volt used to measure? What causes metal to be a good conductor? What causes an electric current to keep moving? What causes an object to build up a static charge?

Lesson 3: What are Electric Circuits? http://www.youtube.com/watch?v=y3yoXh94Vp0

Electric Circuit The wires give the electricity a path to follow. The path an electric current follow is an electric circuit. An electric circuit needs two things for a current to flow. It needs a source of current or electrons and a complete, unbroken circuit. If there is a break in the circuit the current won’t flow. A switch controls the flow of current by opening and closing the circuit.

Series Circuit In a series circuit the current has only one path to follow. The parts are connected in a single loop. Removing one part will break the circuit and the current stops flowing. Series circuits aren’t used for most wires in buildings or homes because in order to work all electric devices will have to be switched on at the same time. If one light burns out none of the others will work.

Parallel Circuit A parallel circuit has more than one path that current can flow. In a parallel circuit if one device is turned off or removed, current stops flowing along the loop of that device but continues to flow to the rest of the circuit. This makes parallel circuit more practical to use than a series circuit. Homes, schools, and buildings are wired with parallel circuits. In this circuit if one light bulb burns out the others remain working. Another advantage of parallel circuits is that you can connect more devices.

Drawing Circuits Engineers design these circuits. Circuit diagrams are symbols to show the parts of a circuit. Each part of a circuit has a different symbol. Some circuits such as a blender or a lamp are simple, but those in a car or a jet plane are more complicated.

Lesson Review If you want a switch to turn a light on and off, should you connect them in series or parallel? Explain. What two things are needed for a current to flow in a circuit? What do you see on a circuit diagram? What are some advantages that parallel circuits have over series circuits? How are homes, schools, and businesses wired?