 Hello, my name is Kevin Conley. I'm an instructor at Foresight Tech. And what I'd like to do is give you a brief introduction to nuclear chemistry. This is the first of a number of lectures I'll be giving on nuclear chemistry. First of all, I'd like to give you a context time-wise as to how the nucleus has been important in chemistry. And this timeline travels through about 110 years. This should give you a context so that when you learn things about decays, reactions, you know where these things are important for normal life, for history, as well as for different things that you may find and come across in your professional life. First of all, in about 1900, the nucleus was really discovered, and radiation was discovered by a number of people. First of all, by Rutherford from New Zealand, who did experiments to show that the nucleus did, in fact, exist. And it was only about 110,000 of the radius of the electron cloud in hydrogen and helium, and also by Curie and Becquerel, who were the ones who discovered that there were different types of radiation coming from nuclei, whether they were alpha, beta, or gamma radiation. So that was about 1900. Then we have to go a ways to put 1940 before the nuclear radiation was really used for any purpose. And in this case, it was used in the 1940s to create the atomic bombs that you are familiar with. First of all, fission bombs in the 40s, and then fusion bombs or hydrogen bombs in the 50s. And then after that, neutron bombs were created afterwards. In the 1950s, though, the energy of nuclear fission began to be harnessed by nuclear fission plants, nuclear plants. And they sprung up all across the United States. And the interesting thing is that they were given 50-year commissions or 50-year licenses. So around the year 2000, 2010, 2020, a lot of these plants are losing their commissions and need to reestablish them. And there have been some successes and some failures. But it's important to note that the safety issues involved in new nuclear plants are significantly greater than they were in the previous plants that were put down in the 50s, 60s, and even 70s. In 1950, it was understood that stars, the thing that powers stars, is related to nuclear reactions as well, the fission and the fusion reactions that occur. And also, when supernovae occur, especially supernovae 1987A that you might want to look into, it's a very exciting case of where the supernova was actually witnessed. And lots of data was taken. Radiocarbon dating became important in 1950 by which artifacts, things that were discovered in ancient Egypt or from the Fertile Crescent, Tigris and Euphrates River, or really things that are only a few hundreds of years old can be used to take a look at the carbon-14, carbon-12 balance. And from this, understand how old an item is, colliders. Colliders began to be used in order to understand subatomic particles, quarks, hadrons, electrons, protons, the structure of different nuclei. These things began to be studied in the 1950s. In 1980 was the first significant accident, the nuclear accident at Three Mile Island in Pennsylvania. People were not hurt during this time. There was a very small amount of leakage, but it really got the attention of people in this country. And actually, it did occur in 1979. I also haven't mentioned here in 1986 there was the nuclear accident in Chernobyl in the Ukraine. That was a very different accident. You can find out now that that accident occurred. And it was months later that people who lived near Kiev actually found out about it. But people in Sweden who received the radioactive plumes of air found out about it that same day. So there were very significant problems there. That's the Chernobyl accident. Medical applications of nuclear chemistry began in about 1980. These are things like we're being involved with PET scans and CAT scans and things of that type. Smoke detectors are a very interesting case of using nuclear radiation. You have a nuclear isotope that releases a certain amount of radiation. But when the smoke comes in between the source and the detector, the emitted radioactive particles don't make it to the detector so that when the current goes down, the whole thing says there must be smoke in the air and it sets off its sound. And then finally, hopefully you're aware of the Fukushima accident that occurred in Japan. It didn't occur in 2010. It did occur in 2012, just trying to simplify the timeline for you. And this is a very significant event because it did involve a tsunami. It does involve a good deal of the water and the natural environment. And it is something that is a continuing problem and an ongoing investigation that I suggest that you look into. We're also going to learn a good deal about a number of different decaying processes, decays. The decays are alpha, beta, gamma, and positrons. And the decays are labeled by the primary type of radiation or the primary type of particle that's going to jump out of the nucleus. And we will talk about these. And you will learn a good deal about these as well. They're given the names of alpha, beta, and gamma because they're the first three letters in the Greek alphabet. Even though that they have very little to do with what actually the things that are coming out. The reactions that we will learn about are bombardment, which is basically what it says. You have a nucleus, and then you're going to throw something in it by bombarding it. There's going to be a change to that nucleus. And we'll take a look at what those cases are. Fission is what happens when a nucleus is going to be split into two parts. And commonly, when there is fission, it will break apart into two parts that are similar in size. And then there is fusion when you take two very small nuclei and you bring them together. And they create a larger nucleus, but still are quite small. So bombardment will occur when you take small particles to hit a large nucleus. Fission will occur when a large nucleus breaks up to form two smaller. And fusion will occur when you take two very small and put them together to form a medium-sized nucleus. I'll see you at the next lecture.