Alright welcome everybody, I just want
to talk to you a little bit about uses
of radioactivity and sort of revisit a
few other things that we talked about
previously with fission and fusion. So
 radioactivity, we've been sort
of giving it a little bit of a bad rap.
When we talk about fission reaction
disasters, radiation poisoning, but it
turns out that if you know somebody is
given radiation in a very small dosage
it could be used to do things like treat
cancer. It could be used as what's known
as a biological tracer, and so these
are some of these types of radio
isotopes that are used in medicine. So
iodine 131 is a big one this is actually
used to either treat the thyroid or to
study its function because the thyroid
does use iodine in its production of
thyroxine. If you want to study red blood
cell function you can use iron 59 that
gets incorporated into hemoglobin.
phosphorus-32 can be used to study eyes,
liver tumor. In a normal lab you can also
incorporate phosphorus into DNA into
that phosphate backbone of the DNA and
you can basically what they call radio
label it. Tecnetium 99, that's used to
study the heart bones liver lungs. Sodium
24 is for the circulatory system. Now
some other uses of radioactivity that
come up on the regents exam carbon-14
this is used to study fossils it has a
half-life of about 5,700 years and so if
you find the remains of an organism you
can determine how old it is based on how
much carbon-14 remains in the fossil.
Once the animal dies it obviously stops
eating it stops incorporating fresh
carbon-14 into its system and at that
point it's sort of like time-stamped and
so if we find the remains of an
organism
thousands or hundreds of thousands of
years ago we can determine its age
pretty precisely based on this type of
radio dating. Another isotope uranium-238
this is used for dating rocks, so if
you're into dating rocks, geology, you
might have learned about this in earth
science and this has a really long
half-life of about four billion years
and so this makes perfect sense, to use
for dating you know something that is
extremely old like a rock formation to
see you know like how old the earth is,
for example. Another use is or another
isotope is cobalt 60- this is used a lot
in cancer treatment so the cancer cells
are growing uncontrollably- if you target
the cancer cells with a really fine beam
of radiation you can re eat those cancer
cells and so this is used as a cancer
treatment.
Cobalt-60 and other isotopes can
actually also be used to sterilize food.
and so if you bombard food with this,
with the radiation then it will kill
microorganisms- make it safer to eat.
You're not adding it to the food, you're
just exposing the food to the
radioactive rays which doesn't make the
food radioactive it just kills any
organisms that are there. Okay so these
are some common uses. The regents likes
to bring this up quite a bit. Some
interesting stories about radiation, so
you know sometimes if you're giving off
these particles you'll cause there to be
some kind of glow, and so they actually
used radium-226, this isotope in watch
dials when they wanted them to glow and
this happened in the early 1920s and a
couple of interesting facts about this-
you know this would make the watch hands
glow so that you could see them in the
dark. This has been largely replaced
today by florescent phospho
fluorescent glowing bands which are not
radioactive. In some cases tritium which is
much less potent than this radium-226
and there's actually some interesting
stories about what they call the radium
girls and you know there were all there
were all these women working in these
watch factories and they were painting
the bands with the radium paint and a
few interesting things as they thought
it was cool and they were told that it
was you know completely harmless to them
so some of them would use it as makeup
or to paint their face and actually
what's really interesting is they were
instructed by their employers to sort of
make the tip of the of the paintbrush
you know to prop it up again they were
told to dab it against their lips
instead of on like a piece of paper or
washing it because it would waste less
paint and so a lot of these women were
you know exposed to high levels of
radiation and either they died or they
got really sick and this was sort of one
of those cases of workers rights you
know during the industrial revolution.
And after that you know where
people were not really protected and
they needed to sort of you know fight
for proper working conditions. I had
mentioned radon before,
and radon is a noble gas it's non
chemically reactive but it's radioactive.
You know it decays and it gives off
particles and it can cause you know
cancers when people are exposed to it
for long periods of time. So
l this is showing you some of those
radon maps and I had mentioned
Pennsylvania. Pennsylvania's over here
and it has  a high level of radon
and then in any other parts 
usually there's  a bedrock base
where  people are basically digging
out a basement and and when they do that
then they're exposing themselves to
radon and so if you ever buy a house in
a region where it's known to have
radon,
buyers should always have that house
tested to make sure that you
don't need to either not buy the house
if you're that concerned or have some
kind of mitigation system put in
where it will sort of remove the
ventilation system, will remove the radon
from the home, so that you won't be
exposed to it. I had also spoken about
safety with with nuclear power plants
and have mentioned Yucca mountain.
and Yucca mountain is this
one-stop storage place where 
people would  store huge
amounts of radioactivity and try and
keep it sequestered- but you know there's
controversy about this. Do we 
want to store the radioactivity in one
spot or do we want to spread it out in
different spots? Depending on what your
philosophy is, what you think would be
wise, that's a big
controversial topic. I've spoken to a lot
about nuclear accidents with Chernobyl.
This is actually a picture of Chernobyl
this was after the accident occurred. You
can tell that there was this
area here that's sunken in and what was
interesting about Russia,   they tried
to cover this up with a really quickly
hastily made, poorly made I would say,
what they call the sarcophagus, and so
this building it was teetering on the
edge of falling down for many years and
so very very recently they're
constructing a new sarcophagus that is
going to be more stable and and
 more state-of-the-art. It's
gonna protect the area around it from
from radiation. Alright, well thanks so
much for watching this nuclear chapter
presentation. I happen to really enjoy
teaching nuclear chemistry. I just think
it's really relevant and  important
for you to understand the science behind
it. You can make your own opinions about
what you think about nuclear power, you
know, and what not, but understanding
the science and sort of having an idea
which you can
actually  base your opinion on,
not just you know what you hear randomly here or there, but what actually you
know truly understand. That to me is
really important. Alright thanks so much
for watching!
