1. Electricity and STEM Lab #5

2. 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.

3. 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.

4. 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.

5. Batteries, Voltage, and Current
Current is measured in Amps. 1 Amp is 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