By Amber Bennett
It keeps our favorite devices charged, our lights and router on, and our appliances running. As much as we rely on electricity, you might not understand exactly how it works or certain terms related to it. Not to worry. Keep reading for a guide to common science terms related to electricity.
First, let's start with electricity itself.
Electricity
Basically, electricity is the energy of charged particles. It also can be described as the flow of electrons (negatively charged particles) from one atom to another. When the electrons are able to move, they can light a lightbulb, power up a cellphone, or give a washing machine the power it needs to run a load of laundry.
Now, let's look at science terms related to electricity.
Battery
A battery is a device used for storing energy. It converts chemical energy into electrical energy. Most batteries include a case, two electrodes, and an electrolyte (the chemical that fills the gap between the electrodes; it often is a liquid or paste-like substance). A battery has a positive electrode (cathode) and a negative electrode (anode).
Capacitor
This is another type of device that can store energy. However, instead of storing it chemically like a battery, a capacitor stores electrical energy physically by collecting large positive charges in one area and large negative charges in another. Simple capacitors have two parts that can conduct electricity (conductors) separated by a gap that cannot conduct electricity. Modern capacitors often have a nonconductor in the gap, such as plastic or ceramic. Capacitors often are used in circuits and electronic devices.
Charge
We can't talk about electricity without talking about charge! This is a fundamental property of matter, like mass. We know that pieces of matter can have two different types of charge (we call them positive and negative) or can have no charge (neutral). Charges can attract or repel other charges (like magnets do). Just like magnets, opposites attract and likes repel.
Electricity is all about the movement of electrons, as they are the only charged particles that aren't held tight to an individual atom. We could imagine the movement of positively charged protons being considered a type of electricity, as well, but that only happens in nuclear reactions — definitely not in your toaster. So, we're stuck with moving electrons, which is accomplished by collecting more electrons in one area (giving that area an overall negative charge) and fewer electrons in another area (giving that area an overall positive charge), then letting electrons get pushed and pulled by the charged areas.
One common way to create these positive and negatively charged areas happens inside a battery.
Circuit
This is the loop-like path that an electrical current takes. When the loop is complete, the current can flow. However, if there is a gap in the circuit (such as from a cut wire or a switch being flipped off), the current stops.
Conductor
A conductor is a material that does a good job of transmitting electrical energy. Some examples of good conductors include saltwater and most kinds of metal. Copper is often used in wiring. Other metals that make good conductors include aluminum, gold, and silver.
Current
The current is the flow of electrical charges, most often from the movement of free electrons (negatively charged particles) from one atom to another. The unit of measurement for current is amperes (amps for short).
Insulator
An insulator is basically the opposite of a conductor. Instead of transmitting an electrical current, an insulator resists the flow. Many types of plastic make a good insulator, which is why many wires have a plastic coating. The electricity will move through the wire (the conductor) but not the plastic (the insulator), keeping people who touch the outside of the wire safe. Other materials that make good insulators include air, glass, rubber, and wood.
Resistance
Resistance describes how easily an electrical current can flow through a conductor and is measured in ohms. An object's resistance varies based on the type of material and its condition. However, even an object with high resistance can be overwhelmed by a large enough current trying to pass through it.
Semiconductor
A semiconductor is a material that sometimes conducts electrical energy (like a conductor) and sometimes prevents conduction (like an insulator). The current is precisely controlled, which is why semiconductors are useful in electronic devices, such as computers. The most commonly used semiconductor is silicon.
Transformers
As you can guess from the name, a transformer is a device that transforms electricity into a different voltage. An example of a transformer you use every day is part of your smartphone charging cord. It reduces the voltage coming through the cord from the wall outlet, so your device isn't fried (common household outlets transmit 120 volts, which is too much for your phone).
Voltage
Voltage is a measurement of how much electrical energy devices can access. It can be stored in batteries and capacitors. Standard outlets in the U.S. offer 120 volts, but special outlets for large appliances offer 220 volts. On the lower end, non-rechargeable AA, AAA, C, and D batteries carry 1.5 volts, while their chargeable counterparts often carry 1.25 volts.
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