Electricity and STEM Lab #5

Activity 1: Electricity and Batteries Consider an atom: electrons and protons are attracted to one another. This attractive force is called voltage. Every battery has two terminals: + and – A chemical reaction inside the battery separates protons and e–. Once we connect a conductor to the battery, electrons (–) are allowed to flow toward the protons (+), producing electricity. electrical current = the rate of electrical flow If there’s a bulb (or and LED in our case) in the electrical path, it will light up, as long as we have a closed circuit. Turning on a light switch “closes” the circuit.

What did you notice about the LED’s? LED = light-emitting diode In a diode, electricity flows in only one direction post = positive anvil = negative when connected correctly, we have a complete circuit.

Batteries, Voltage, and Current LED’s require 1-2 volts to operate, but our batteries had 3 volts. Question: So why didn’t the LED burn out? Answer: The reaction in the battery can’t produce all 3 volts at once. All batteries have this limitation.

Batteries, Voltage, and Current Current is measured in Amps. 1 Amp is 6.241 x 1018 charges (electrons) per second going through the wire. A measure of a battery’s total storage or “life” is measured in Amp Hours (Ah). A battery with 20 Amp Hours will produce 20 Amps for 1 hour The batteries in our lab produced only about 0.01 Amps. If our batteries have a rating of 0.25 Ah, how long will they make our lightstick work for? 25 Hours