They are called "free electrons". This makes them good conductors. Condu tors are materials that allow electricity to flow easily. When a negative charge is brought near one end of a conductor electrons are repelled.
When a positive charged object is placed near a conductor electrons are attracted the the object. Metals contain free moving delocalized electrons. When electric voltage is applied, an electric field within the metal triggers the movement of the electrons, making them shift from one end to another end of the conductor.
Electrons will move toward the positive side. Copper is a good conductor because the outer most electrons from the nucleus are weekly bound and repulsive, such that a small perturbance, like a potential difference between two ends of a wire, can knock the valence electrons from an atom free, which then perturb the neighboring valence electrons and so on resulting in a cascade disturbance of moving charges or current throughout the material.
The energy required to free the valence electrons is called the band gap energy because it is sufficient to move an electron from the valence band or outer electron shell, into the conduction band where upon the electron may move through the material and influence neighboring atoms. The above following diagram illustrates this concept. Insulators are materials where the electrons are not able to freely move.
Examples of good insulators are: rubber, glass, wood,. A battery converts chemical energy into electrical energy by a chemical reaction. Usually the chemicals are kept inside the battery. It is used in a circuit to power other components. A battery produces direct current DC electricity electricity that flows in one direction, and does not switch back and forth as is with AC alternating current.
Details Activity Length 10 mins. You need three things in order to make a c omplete circuit: a conductor e. In this activity: students are the electrons energy provided by the battery is represented by smarties. A Fuse. Fuse Box. Objectives Describe the components required to complete an electric circuit. Materials Per Group: students stool, chair or box masking tape box of Smarties or suitable small, nut free candy Key Questions How could we increase the current in other words, how can we make the electrons move faster?
What To Do Students form a circle to represent the wire. It may help to tape a circle on the floor or use a circle marked on the gym floor. Explain that the students are electrons.
There are always electrons in the wire, and they are always moving randomly, a little bit in every direction. Choose one of the students to be the power source battery. The closest student to the battery moves forward to get a Smartie. As soon as the electrons start moving in one place, they start moving everywhere. As the electrons pass the battery, they get energy Next pick someone to be a switch. The switch, when off, will completely stop the electron movement.
Now put a stool or a chair or a box in the circle. This represents a resistance. The electrons have to climb over the stool to move forward. The whole electron chain will slow down, showing that the current slows down when there is a resistance. How could we convince the electrons to move faster through the resistance? We could pass out more smarties! That's all an electric current is — electrons moving in an organised way.
The energy to get the electrons moving in an organised way comes from either a battery or a generator. When a battery organises electrons they all move in the same direction at the same time — the battery pumps electrons through the circuit wires from the negative terminal to the positive.
Because they're all going in one direction, it's called a direct current DC. The electricity generators at power stations organise electrons in a slightly different way. They pump electrons, but they change the direction they're pumping them times every second. So instead of moving along in one direction like in a DC circuit, the electrons stay pretty much where they are and constantly jiggle forwards and backwards. If you could see inside the power cord when an appliance is turned on, you'd think the electrons had just learned how to line dance — they're all constantly taking one step forward, one step backwards in synch.
The constantly changing direction is what's behind its name, alternating current AC. So a current is just electrons moving in an organised way in a circuit. But how do electrons on the run make the heat that's behind toasting, drying and foot warming? All wires get a little bit hot when they've got a current running through them, because as the electrons move in the wire they bang into the metal atoms.
And whenever they prang into an atom, energy from the moving electrons gets given off as heat. We use copper for electrical wiring because it's easy peasy for electrons to move around in, so not too much energy gets wasted as heat. You just need to use a bit of metal that's really hard for electrons to move through, like nickel. Run a current through nichrome and you'll get some serious heat. While the electrons in the copper wires can move around easily, the ones in the nichrome element are constantly banging into the nickel and chromium atoms and leaking heat all over the place.
Which is just what you want on those wet-haired, stale bread days. But heating is only one of the things electric appliances can do. Most of the other things involve making things move - and that involves a motor. So how do organised electrons make a motor spin? Every appliance with moving parts more complex than a pop-up toaster has got an electric motor in it. And while they run thousands of different gadgets, electric motors really just do one thing — they spin whenever you turn on the power.
And anything attached to them — like fan blades, wheels or washing tubs — spins too. The spinning only happens when current is flowing — when electrons in the wire are organised into a current.
So how do moving electrons make a motor spin? They don't.
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