Greetings fellow nerds.
As many of you know, rusting is a problem for a number of items made of iron.
While using better metals like stainless steel alloys is one option,
another is to protect them by zinc galvanization.
In this video we're going to do just that.
First make a solution of zinc sulfate by simply mixing 30g of zinc sulfate with 100mL of water.
Now here are the two clean iron nails we're going perform this experiment on.
I will plate one of them and leave the other as a control experiment.
These clips lead to a 5-volt power supply off-camera.
Take the nail and clip the negative terminal of the power supply to it.
Now with the positive terminal clip it to a strip of zinc metal. 
Place the two electrodes into the zinc sulfate solution and make sure they don't touch.
Now turn on the power and run the current for about a minute or two.
The positive terminal with the zinc strip is dissolving and putting zinc ions into solution.
 While the negative terminal is reducing the zinc ions
and plating them onto the nail as zinc metal.
Some hydrogen is also released and can be seen as the bubbling around the nail.
After about a minute turn off the power and remove the electrodes.
You can see here the distinct coating of zinc metal on the surface of the nail.
This is what we call a galvanized nail.
Let me bring it over to the microscope.
Here are the two nails,
the galvanized one at the bottom and the untreated nail at the top.
The galvanized nail has a rough coating of tiny zinc crystals
that gives it the slightly lighter appearance compared to the untreated nail.
The coating is not perfectly continuous with the whole nail but it doesn't have to be.
Let's test the rust resistance.
Take a dish with a paper towel soaked in dilute salt water.
Then we place on it the two nails,
put them about a centimeter or so apart, and cover it to prevent evaporation.
This setup exposes the nails to air and water
the two required components for rusting.
Now we just leave it overnight.
Here we are the next day.
We can see the nail on the left is rusting and leaving behind iron oxide on the paper towel.
The galvanized nail on the right doesn't seem to be damaged that much if at all.
Let's take look  at it under the microscope.
Now you can clearly see the rust on the untreated nail.
The galvanized nail at the bottom instead has this white powder.
In truth, actually both nails are corroding,
but in the galvanized nail the zinc metal corrodes first
because it's more reactive
and produces this white powder of zinc hydroxide and carbonates,
essentially zinc rust.
That's why some old galvanized poles, sheeting and fences have this white crust on them;
it's actually zinc hydroxide and carbonate.
Now when the zinc corrodes it gives off electrons
that go into the iron and give it a negative charge.
This negative charge prevents the iron from rusting.
So even though the zinc does not cover the whole object,
the electrical charge does
and thus you don't need to completely galvanize an object in order to protect it.
You just need to galvanize most of it
and even those exposed parts will still be protected thanks to the negative charge.
Thus why this nail is almost completely rust free.
Now galvanization doesn't last forever,
eventually the zinc itself will be completely used up
and rusting will set in again on the iron.
Nonetheless it's still a very long time and can last years.
Now nails can be bought already galvanized
but you can use this technique to galvanize just about anything made of metal
so feel free to experiment.
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