Welcome to part three of my series on
how elements react with a magnet. I have a few but fantastic samples
that I can’t wait to show you. So let’s start. First up is calcium.
A quite common metal. An average adult has around
one kilogram of calcium In the bones – 10 times more
than in this bottle. Calcium is attracted to a magnet so it’s paramagnetic.
It is also quite a good electrical conductor. Around three times better than iron so
when I move the magnet too fast eddy currents are generated in the calcium.
These eddy currents repel the metal away from the magnet when the magnet is coming fast towards
the metal but they attract the metal towards the magnet when the magnet is moving fast away from
the metal. The paramagnetism attracts the metal when the magnet
is steady or moving very slowly. Calcium attracts a magnet about
as much as tellurium repels one. Vanadium is an important element used in for example the durable
chrome-vanadium steel for tools. This nice sample is crystals
stored under argon. It is just paramagnetic enough
to wiggle near a magnet. And lift a magnet a little on a scale.
Notice the minus reading. On the highly sensitive water bath it is
very clearly attracted to the magnet. Vanadium attracts a magnet about
as much as bismuth repels one. Phosphorus is a very reactive element.
Mixed with glass powder and glue it is found on the side of matchboxes
so you’re only one flick away from releasing the destructive force of fire. Phosphorus should repel a magnet but this sample attracts. This is
a good example of why high purity is important when testing elemental properties.
This sample is minimum 98% pure. But 1% impurity of iron
compounds is more than enough to counteract the weak
diamagnetism of phosphorus. I doubt I will ever test a
better phosphorus sample though. It still was a good one. Arsenic is an infamous, toxic metalloid – so this 107 g sample made my heart beat a little faster.
Stay away from this s**t! For safety reasons this is a vacuum pack inside a vacuum pack
making it a little hard to film the arsenic. But it looks innocent – just like scrap metal. A magnet reveals that this isn’t rusty iron. I could not see a reaction. Arsenic
is a very weak diamagnetic metalloid. Almost neutral. The next sample may be the most dangerous I will ever show. Take a
close look at these warnings… It is a small sample of fatal thallium. This sample is corroded but
you can see the shiny metal at the edges where the metal has scraped
against the glass. Thallium is a very soft metal that can be cut with a knife.
With such a small sample in a heavy wrapping I just couldn’t get a reaction even
though thallium is more diamagnetic than vanadium is paramagnetic. A bigger,
naked sample should easily show the diamagnetism on a water bath. But I’m not looking for such a sample.
Neither should you… Having survived these nasty ones let’s finish
off with a couple of new and beautiful samples from my own collection. This is the awesome osmium!
A tiny sample but it still weighs over 2 g so it has
a cute friction noise against the glass. With such a small and dense sample I need to ramp up my test to show
that it is paramagnetic. The trick is to use a sphere magnet.
Its shape gives it a tiny but powerful magnetic field on the poles. To find one of the poles on the magnet
I use another one. They will automatically line up
pole to pole. With one pole here the other pole
is right there. The second magnet is also a practical handle. Let’s test
if this will show osmium’s paramagnetism. Look for an attraction. It’s so weak but I’m happy to see it works.
Also notice the beautiful blue tinge of osmium. Since I started this video series
back in early 2012 One element has been requested the most. I hear you. I have saved up for some gold. At 5 g it’s not a large sample
but it’s all I could afford. Taking it out of the original seal
could make it difficult to sell it again so I’m not gonna open it. Naah – just kidding.
In the name of science I shall set you free! With the candy out of the wrapping
you get the full experience. Gold is a stunning element. Alright, it is finally time to test
if gold really is diamagnetic. Yes – it repels a magnet. Gold is an excellent electrical
conductor so fast movement of the magnet generates eddy currents in the gold.
But a steady magnet shows the repelling force of diamagnetism. Let’s just for the fun of it imagine that someone claimed this watch
bracelet to be solid 24K gold. It is obviously not. 24K gold is too
soft to be used in jewelry and watches but play along. He would say:
– Look! It’s the right color and it’s not magnetic! True dat. But does it repel a magnet
in a sensitive setup? Nope. This is clearly not solid 24K gold. It is actually stainless steel
electro-plated with 18K gold. Just an extremely thin layer
so practically worthless. Much better fake gold bars with a
tungsten core have been made. So never trust a magnet alone. On the scale
I could barely detect the diamagnetism. The gold is not touching the magnet.
It is just repelling the magnet to give a plus reading. This would be easier to detect with a
scale that could measure milligrams. Also notice the larger minus reading
when I quickly move the gold away. This is of course the magnetic field of the
eddy currents being generated in the gold. Now, I couldn’t resist gathering these
three elements for a family photo. One kilogram of copper, ten grams of cesium and five grams of gold. Can you guess what alloy this is? I’ll give a little shoutout in one of my next videos
to the one who first write a comment with the right answer. I have shown you exactly 60 elements now. Can I get you
to press ‘Like’ to celebrate this anniversary? Anyway, thanks for watching this far.
Hope you enjoyed it!