Mr. Andersen describes the major groups on the periodic table.
Transcript Provided by YouTube:
Hi. It’s Mr. Andersen and today I’m going to take you on a tour of the periodic
table. A book that I’ve been reading, I’m not quite done but it’s really fascinating
is called The Disappearing Spoon. It’s written by this guy over here. His name is Sam Kean.
If you want more information you can go to samkean.com. It’s neat. It’s got a lot of
trivia on periodic table. But it’s essentially about the history of the periodic table. In
other words it’s not the science which I’m going to talk about today. It’s more about
the people who discovered the elements. It goes all the way from the Manhattan Project
to Mr. Bunsen, the inventor of the Bunsen burner. And Mr. Lewis, famous for Lewis Dot
Diagrams. So it’s fascinating read. And it’s getting at the history behind this. Which
is periodic table. Periodic table we’re going to come back to this in just a second and
we’ll review some of the things from this podcast. The thing you maybe puzzled about
is what’s up with the name of the title, The Disappearing Spoon? Disappearing Spoon is
actually written about this element. It’s called Gallium. It’s a poor metal. And the
neat thing about gallium is that it has a really low melting point. And so if you mix
your tea with a spoon made of gallium, so let’s take a look at the video over here on
the side. The minute it goes in the tea you can see that it starts to turn into a liquid
and then kind of melts away. Thus, The Disappearing Spoon. The problem with this, I was like you,
I was saying let me google it. Let me buy one of these spoons. It seems cool. It’s also
highly radioactive. And so it may not only be a disappearing spoon, but it may be a disappearing
hand if you deal with gallium too much. So let’s get to the periodic table. So here’s
our periodic table. Periodic table, first of all, the vertical columns are going to
be called groups. And so this would be 1 and 2 and 3 and it goes all the way over here
to number 18 which is on the side. And the periods are going to go down the side. So
this would be 1, 2, 3, 4, 5, 6, 7. And so we’re going to see these periodic properties.
In other words as we go and look period to period to period. You’ll find that there are
similar characteristics. Let’s go through it then. And I’m going to try and use different
colors and highlight each of the different areas. So let’s start with the first one.
First ones are going to be these metals. These metals are called the alkali metals. And it
goes all the way from lithium at the top to cesium at the bottom. So these are called
alkali metals. Alkali metals all have one valence electron. That means that they’re
highly reactive. And so in this picture down here we’ve got lithium, sodium all the way
through cesium. If you want to have fun on YouTube just look at alkali metals and you’ll
see people thrown into water and you get these huge explosions. And that’s because of their
valence electrons. Next to them are called the alkaline earth metals. So let me advance
our picture. So these are the alkaline earth metals. It goes all the way at the top with
beryllium all the way down to the bottom at radium. So this is alkaline. These all have
two valence electrons. And so they’re reactive as well. They tend to form oxides with oxygen.
Magnesium, calcium, all these are important in living things. And they tend to be fairly
stable. In other words we can find them on our planet in a raw form. Next up. We’ve got
the halogens. Halogens are going to be over here on this side. So this would be a halogen
right here. Fluorine, chlorine, bromine, iodine, astatine. These all have seven valence electrons.
So that means they would love to get one more electron. So they’re not super stable. Chlorine
pictured here in this block is in a liquid form. It normally occurs as a gaseous form.
It’s a nasty gas. It was used as a poison during World War I. And these are the halogens
right here. Highly reactive. Right next to them however are the most unreactive of the
elements that we have. And these are going to be called the noble gases. So helium, neon,
argon, krypton, xenon and radon. All of these have 8 valence electrons. And these are going
to be called the noble gases. Really stable. They’ve got complete outer energy levels or
valence shells. So they’re really, really happy. Unlike their halogen neighbors which
are right next to them. Okay. Cool thing about them if you look down here at this picture,
you put any of the noble gases in a tube, run electricity through it, they’re going
to fluoresce as electrons kind of move to higher energy levels and then fall back down.
So if you look at neon lights or lasers are all made up of these noble gases. And if you
ever heard of inert gases, inert gases are gases that don’t react with anything. We use
those in like mig welding be it an application of that. Okay. Next are the CHNOPS. CHNOPS
are a way that I like to remember the non metals. And so I’m going to circle these.
So here’s carbon. And I’m going to go way over here and circle hydrogen. And then we’re
going to do nitrogen and oxygen and phosphorus and sulfur and selenium. So these are all
called the non metals. The reason I wrote down CHNOPS is that these are all things that
are vital inside living material. So carbon is what we’re made up of. Nitrogen makes amino
acids. Oxygen is used to get energy out of our food. We use phosphorus in our DNA. Sulfur
in our proteins. And even selenium, which is not part of CHNOPS, we need micro amounts
of that. And it’s been linked to deficiencies in selenium can actually, perhaps cause cancer.
Okay. Next one then is going to be the transition metals. And so if we were to circle those
on here, transition metals are going to be all these down here. These are the transition
metals. Transition metals have weird numbers of electrons. In other words the ones that
they’re showing outside are variable. And so they all look the same but they all have
different characteristics. And so these are called the transition metals. Example would
be gold. And so gold is going to be right here as a transition metal. And here is a
block. This is the largest block ever of gold. I think it’s 250 kilograms. So like 600 pound
bar of gold. Neat things again in that verticality, silver is right about that. Copper is right
above that. They have similar valence electrons and so these are all going to be similar.
Next group then on the periodic table is going to be the poor metals. And so if we go to
where those poor metals are, poor metals, let me find a good color, poor metals are
going to be, let’s go right here. And here. And here. These are going to be the poor metals
in here. And so metals are going to be over in this group. This is gallium right. This
is a picture of gallium that was that disappearing spoon remember that melted away right at the
beginning. These are going to be somewhat good conductors, but not as good as the true
metals that we find over here. And the transition metals. Next group then are going to be the
metalloids. And so a good color might be red if I could find that. There we go. So the
metalloids are going to be here. So that’s boron, silicon, germanium, arsenic, antimony,
tellurium and polonium. These are all going to be the metalloids. And these are all semi-conductors.
And what that means is that they conduct electricity but the don’t fully conduct electricity. I’ve
got a block of one of them. This is actually a lug or a large amount of silicon. And so
this is a silicon crystal. What they do is they grow it into these great cylinders. And
then they slice it off. And then they can stamp silicon chips out of it. So it feels
a little bit lighter than it would if this was just a true metal like iron for example.
And if we run electricity through it we can kind of control the amount of electricity
that we run through that. Because it’s a metalloid or a semi-conductor. And then the last thing
I put on here was uranium. There’s a general trend that as we go farther and farther and
farther down the periodic table our size is going to get larger and larger and larger.
So when we get down to things like uranium, these are actually uranium cubes that were
used in the Manhattan Project. Atoms are going to get larger and larger and larger. So when
we go down to the bottom this is uranium, most uranium is in the form of uranium 238.
That means it has 92 protons and tons and tons of neutrons. And so the farther we go
down the periodic table things tend to get radioactive. In other words parts of them
tend to decay or to fall apart. One other interesting part here, this is the lanthanides
and the actinides. The way a periodic table really should be organized is that these two
rows here at the bottom should actually be inserted here. And the reason that most periodic
tables don’t show it that way is it would make our periodic table incredibly long. And
so really wouldn’t display well on poster.
This post was previously published on YouTube.
Photo credit: Screenshot from video.