1 article
1 program
12 videos
Basic observations leading to homemade batteries

Zinc copper cell (reduction-oxidation)

VIDEO 1:05 minutes
Zinc Copper cell - example of reduction-oxidation reaction

Battery meter (galvanometer)

VIDEO 0:50 minutes
Simple device which we can use to measure our homemade batteries. You can test it with any household battery first. What does this deflection represent? What forces are involved?

How Many Turns?

how many times should your wrap your wire around the compass?

Electrolyte test (pure water vs. vinegar)

VIDEO 1:23 minutes
First we attach our galvanometer to a piece of copper and zinc. Then we submerge the metals in pure water and vinegar. What is the difference? Why?

Reverse electrodes (polarity)

VIDEO 1:23 minutes
What happens to the deflection when we attach the penny and zinc in the opposite direction?

Electrolyte (strong acid test)

VIDEO 0:44 minutes
Experimenting with a strong acid as electrolyte and observing the change in deflection compared to weak acid (vinegar)

Electrolyte (salt test)

VIDEO 1:04 minutes
What happens to the deflection when we add salt to an electrolyte? Why?

Electrode (distance test)

VIDEO 1:06 minutes
Does the distance between the copper and zinc electrodes matter? What happens to the deflection when we hold them close vs. far apart? Why is there a difference?

Electrolyte (temperature test)

VIDEO 1:37 minutes
Here we experiment with hot vs. cold vinegar as our electrolyte. Does the deflection in our galvanometer depend on temperature? Why?

Electrode (surface area test)

VIDEO 1:07 minutes
What's the difference between one piece of metal and three pieces of metal in our cell. Does deflection change? Why?

Standard cell

VIDEO 1:09 minutes
Testing out a cell which holds the metals at a constant distance. We add it to salt water and then check the deflection. Can this be used as a standard unit?

How much electrolyte does a single cell need?

VIDEO 0:40 minutes
Observation: when we pull our cell out of the electrolyte it still causes a deflection, which increases when pressure is applied. How could this lead to more efficient batteries?

The battery and electromagnetism

VIDEO 6:26 minutes
The key technologies in our story.