 Now let's talk about uranium. Uranium has two big isotopes that I want to talk about. Most of the uranium you dig out of the ground is uranium 238. So uranium 238, it's got 92 protons, so 92 protons, and it has 238 minus 92 neutrons, which is 146 neutrons. I didn't do that in my head, I calculated it before. So when you dig uranium out of the ground, most of it is this uranium 238. Now that has some uses. It's quite heavy. Uranium is quite heavy. It's a very heavy metal. But in terms of uses for nuclear projects like in nuclear power stations on nuclear bombs, uranium 238 isn't as radioactive as uranium 235 is. So uranium 235, it still has 92 protons. But this time it's got 235 minus 92 neutrons. And here you spell it right, which is 143, I believe, 143 neutrons. So when you dig uranium out of the ground, most of it is 238, a very small portion is 235. But this isn't useful if you want to use uranium in a nuclear power station or in a bomb. So you want to make more of the more radioactive substance because that's more likely to do the nuclear reactions required for your power station or your bomb to work. So what they do is they enrich uranium. They increase the proportion of uranium 235 to 238. All uranium is going to react very similarly. They have the same number of electrons. The difference between them though is uranium 238 is heavier than uranium 235. So what they do is they turn uranium into a gas and then they spin that gas around really, really quickly. The heavier gas flies out faster and further than the lighter gas. So the gas that contains the uranium 238, that flies out of these things called centrifuges, goes further and further from the middle than the uranium 235 gas does. And what they do then is they condense that gas back. They turn it back into solid uranium and that increases the proportion of uranium 235 to around about 5%. Once they do that, it's useful in power stations or bombs because you have more uranium 235 that's more radioactive. So when you're running your nuclear reactions, they run faster. The last asset that I'm going to talk about is americium 241. So I'm going to ask you some questions about it. How many protons are there in the americium 241 nucleus? How many electrons are around the americium 241 nucleus? How many neutrons are in the americium 241 nucleus? Okay, so americium 241, we have 95 protons. We have 241 minus 95 neutrons, which is 146. You can check my math, I think I'm right. So 146 neutrons. Number of electrons in a neutral atom is equal to the number of protons. So 95 electrons around americium 241. Okay, so today on Flipping Science we looked at what isotopes are, how to calculate the numbers of protons and neutrons given the symbols of isotopes and some possible uses of isotopes. That's it for Flipping Science Day. See ya.