A Tour of the Periodic Table


Mr. Andersen describes the major groups on the periodic table.


Transcript Provided by YouTube:

00:04
Hi. It’s Mr. Andersen and today I’m going to take you on a tour of the periodic
00:09
table. A book that I’ve been reading, I’m not quite done but it’s really fascinating
00:13
is called The Disappearing Spoon. It’s written by this guy over here. His name is Sam Kean.
00:19
If you want more information you can go to samkean.com. It’s neat. It’s got a lot of
00:23
trivia on periodic table. But it’s essentially about the history of the periodic table. In
00:29
other words it’s not the science which I’m going to talk about today. It’s more about
00:34
the people who discovered the elements. It goes all the way from the Manhattan Project
00:37
to Mr. Bunsen, the inventor of the Bunsen burner. And Mr. Lewis, famous for Lewis Dot
00:43
Diagrams. So it’s fascinating read. And it’s getting at the history behind this. Which
00:49
is periodic table. Periodic table we’re going to come back to this in just a second and
00:54
we’ll review some of the things from this podcast. The thing you maybe puzzled about
00:58
is what’s up with the name of the title, The Disappearing Spoon? Disappearing Spoon is
01:02
actually written about this element. It’s called Gallium. It’s a poor metal. And the
01:07
neat thing about gallium is that it has a really low melting point. And so if you mix
01:11
your tea with a spoon made of gallium, so let’s take a look at the video over here on
01:16
the side. The minute it goes in the tea you can see that it starts to turn into a liquid
01:22
and then kind of melts away. Thus, The Disappearing Spoon. The problem with this, I was like you,
01:29
I was saying let me google it. Let me buy one of these spoons. It seems cool. It’s also
01:34
highly radioactive. And so it may not only be a disappearing spoon, but it may be a disappearing
01:39
hand if you deal with gallium too much. So let’s get to the periodic table. So here’s
01:45
our periodic table. Periodic table, first of all, the vertical columns are going to
01:50
be called groups. And so this would be 1 and 2 and 3 and it goes all the way over here
01:56
to number 18 which is on the side. And the periods are going to go down the side. So
02:01
this would be 1, 2, 3, 4, 5, 6, 7. And so we’re going to see these periodic properties.
02:11
In other words as we go and look period to period to period. You’ll find that there are
02:15
similar characteristics. Let’s go through it then. And I’m going to try and use different
02:21
colors and highlight each of the different areas. So let’s start with the first one.
02:25
First ones are going to be these metals. These metals are called the alkali metals. And it
02:30
goes all the way from lithium at the top to cesium at the bottom. So these are called
02:35
alkali metals. Alkali metals all have one valence electron. That means that they’re
02:41
highly reactive. And so in this picture down here we’ve got lithium, sodium all the way
02:45
through cesium. If you want to have fun on YouTube just look at alkali metals and you’ll
02:50
see people thrown into water and you get these huge explosions. And that’s because of their
02:55
valence electrons. Next to them are called the alkaline earth metals. So let me advance
03:01
our picture. So these are the alkaline earth metals. It goes all the way at the top with
03:05
beryllium all the way down to the bottom at radium. So this is alkaline. These all have
03:13
two valence electrons. And so they’re reactive as well. They tend to form oxides with oxygen.
03:19
Magnesium, calcium, all these are important in living things. And they tend to be fairly
03:26
stable. In other words we can find them on our planet in a raw form. Next up. We’ve got
03:33
the halogens. Halogens are going to be over here on this side. So this would be a halogen
03:37
right here. Fluorine, chlorine, bromine, iodine, astatine. These all have seven valence electrons.
03:44
So that means they would love to get one more electron. So they’re not super stable. Chlorine
03:49
pictured here in this block is in a liquid form. It normally occurs as a gaseous form.
03:54
It’s a nasty gas. It was used as a poison during World War I. And these are the halogens
04:00
right here. Highly reactive. Right next to them however are the most unreactive of the
04:06
elements that we have. And these are going to be called the noble gases. So helium, neon,
04:11
argon, krypton, xenon and radon. All of these have 8 valence electrons. And these are going
04:18
to be called the noble gases. Really stable. They’ve got complete outer energy levels or
04:26
valence shells. So they’re really, really happy. Unlike their halogen neighbors which
04:31
are right next to them. Okay. Cool thing about them if you look down here at this picture,
04:37
you put any of the noble gases in a tube, run electricity through it, they’re going
04:42
to fluoresce as electrons kind of move to higher energy levels and then fall back down.
04:47
So if you look at neon lights or lasers are all made up of these noble gases. And if you
04:51
ever heard of inert gases, inert gases are gases that don’t react with anything. We use
04:57
those in like mig welding be it an application of that. Okay. Next are the CHNOPS. CHNOPS
05:04
are a way that I like to remember the non metals. And so I’m going to circle these.
05:10
So here’s carbon. And I’m going to go way over here and circle hydrogen. And then we’re
05:16
going to do nitrogen and oxygen and phosphorus and sulfur and selenium. So these are all
05:23
called the non metals. The reason I wrote down CHNOPS is that these are all things that
05:30
are vital inside living material. So carbon is what we’re made up of. Nitrogen makes amino
05:34
acids. Oxygen is used to get energy out of our food. We use phosphorus in our DNA. Sulfur
05:40
in our proteins. And even selenium, which is not part of CHNOPS, we need micro amounts
05:45
of that. And it’s been linked to deficiencies in selenium can actually, perhaps cause cancer.
05:51
Okay. Next one then is going to be the transition metals. And so if we were to circle those
05:56
on here, transition metals are going to be all these down here. These are the transition
06:03
metals. Transition metals have weird numbers of electrons. In other words the ones that
06:08
they’re showing outside are variable. And so they all look the same but they all have
06:13
different characteristics. And so these are called the transition metals. Example would
06:18
be gold. And so gold is going to be right here as a transition metal. And here is a
06:22
block. This is the largest block ever of gold. I think it’s 250 kilograms. So like 600 pound
06:31
bar of gold. Neat things again in that verticality, silver is right about that. Copper is right
06:37
above that. They have similar valence electrons and so these are all going to be similar.
06:42
Next group then on the periodic table is going to be the poor metals. And so if we go to
06:48
where those poor metals are, poor metals, let me find a good color, poor metals are
06:54
going to be, let’s go right here. And here. And here. These are going to be the poor metals
07:03
in here. And so metals are going to be over in this group. This is gallium right. This
07:08
is a picture of gallium that was that disappearing spoon remember that melted away right at the
07:14
beginning. These are going to be somewhat good conductors, but not as good as the true
07:21
metals that we find over here. And the transition metals. Next group then are going to be the
07:27
metalloids. And so a good color might be red if I could find that. There we go. So the
07:32
metalloids are going to be here. So that’s boron, silicon, germanium, arsenic, antimony,
07:38
tellurium and polonium. These are all going to be the metalloids. And these are all semi-conductors.
07:48
And what that means is that they conduct electricity but the don’t fully conduct electricity. I’ve
07:54
got a block of one of them. This is actually a lug or a large amount of silicon. And so
08:02
this is a silicon crystal. What they do is they grow it into these great cylinders. And
08:07
then they slice it off. And then they can stamp silicon chips out of it. So it feels
08:13
a little bit lighter than it would if this was just a true metal like iron for example.
08:19
And if we run electricity through it we can kind of control the amount of electricity
08:23
that we run through that. Because it’s a metalloid or a semi-conductor. And then the last thing
08:30
I put on here was uranium. There’s a general trend that as we go farther and farther and
08:36
farther down the periodic table our size is going to get larger and larger and larger.
08:42
So when we get down to things like uranium, these are actually uranium cubes that were
08:46
used in the Manhattan Project. Atoms are going to get larger and larger and larger. So when
08:50
we go down to the bottom this is uranium, most uranium is in the form of uranium 238.
08:54
That means it has 92 protons and tons and tons of neutrons. And so the farther we go
09:00
down the periodic table things tend to get radioactive. In other words parts of them
09:05
tend to decay or to fall apart. One other interesting part here, this is the lanthanides
09:10
and the actinides. The way a periodic table really should be organized is that these two
09:15
rows here at the bottom should actually be inserted here. And the reason that most periodic
09:21
tables don’t show it that way is it would make our periodic table incredibly long. And
09:25
so really wouldn’t display well on poster.


This post was previously published on YouTube.

Photo credit: Screenshot from video.