13 1 Nuclear Equations and Radiation

all right guys and gals welcome back it is the beginning of the end we’re at the first chapter of the last unit so we’re going to be talking about today is how you would go about writing a nuclear equation and we’re also going to talk about radiation of a little bit the video that you guys watched earlier was kind of intended to introduce this concept to you guys a little bit and what can I see how this goes so the first thing I need to teach you guys is how to write what’s called a ZX notation now a ZX notation is just a special way of writing the symbols for basically the atoms in our nuclear equations so as you guys can read from the little diagram right here the mass number is represented by a it’s equal to the number of protons plus the number of neutrons so I’m just gonna make a little note here I want you guys to as well so if you guys remember the mass of an atom is protons plus neutrons the atomic number is repeated down here it’s the Z number so just protons and the ax is the symbol now you hear n used all the time it’s just going to be the number of neutrons we’ll talk more about that later so if I were going to write helium using a ZX notation well the first thing I need is a periodic table keep mind you can get these off the website pretty easily you should also have a copy with you so here’s the deal if i look at helium helium has a mass of four and has two protons so if i’m going to put this guy in a ZX notation it’s going to be for over two and then the symbol for helium is a chi the four is the mass the two is the charge or protons in this case and the Aichi is the symbol now I want you guys to try and do this one on your own see if you can put lead in the exact same format use your periodic tables alright well lead Cory new IP route table has a mass of 207 has 82 protons and the symbol for wed is PB so as you guys can see this is actually a fairly easy way of doing this it’s very typical all right so most of the time we use this to show isotopes because nuclear equations guess what they’re for so from chapter 3 we know that isotopes are essentially the same element but they have different masses because of their neutrons so I want you guys to take all of these things and turn them all into a ZX notation now I do want you guys to notice and if you guys don’t remember this I’d be surprised but isotopes the only way to tell them apart from each other is their mass so whatever you guys look at these things the one you see here the 235 you see there the three the to hear they’re all the same thing there are masses now here’s the other side to this keep mind there’s actually several different ways i can show an isotope this is called dash notation that’s where i use the full name dash the mass examples three and four are both like that this is a shortened form of that so it’s the symbol dash the mass and then sometimes you’ll see it written like this which is actually just an abbreviated form of a ZX notation where i show the symbol and then i just show the mass of that element or isotope right above it my top so here’s how we’re going to do this I’m going to work the I’ll work a few of these guys and you guys are going to work the rest I’m going to bounce around a little bit okay if i want to show hydrogen one which is also called protium okay go into my periodic table has a massive one has one proton and the symbol for this guy is H just like that now your rhenium 235 I go to my periodic table again I’m going to see that I have a mass of 235 the atomic number the number of protons of uranium is 92 and the symbol of course is you entreaty ‘um it’s pretty straightforward it’s the version of hydrogen that has a mass of three it’s still hydrogen so it has one proton and its symbol as age okay I want you guys to try the rest okay keep mine these are isotopes the masses of these may not agree with what’s on the periodic table but they all still have the right number of protons to be considered this element so give it a try all right well carbon-14 this is the mass right here so it’s 14 and carbon has an atomic number of six its symbol as see and there’s carbon-14 deuterium would be 2 over 1 H carbon-12 will be 12 over 6 C k40 would be potassium-40 and it would be 40 / 19 k and oxygen 18 would be 18 over 80 okay hopefully you got all these on your own it’s pretty straightforward Gus not all that complicated I do want you to notice I’m not messing with electrons at all

because they really don’t matter here not all that much all right so with that said I want you guys to be able to go back and forth between a ZX notation and the other ways of writing isotopes so I’ve already shown you guys an example right here so this is copper 64 keep mine the mass numbers up top and a ZX notation the 29 just simply tells me that this is element number 29 in that case it is copper cl2 number 29 alright so example 12 I just focus on the mass this is going to be oops I know why I put a cue their oxygen 16 or i could put 16 oh like that or I could write it as 0 16 all three of these mean the same thing along with this it makes four different ways of writing the same thing I want you guys to try 13 14 and 15 on your own make sure you’re using a periodic table all right again I focus on the mass this is sodium 24 or 24 na like that or na dash 24 they all mean the same thing this guy would be boron 11 or 11 be just like that or be 11 and this guy is iodine and he has a mass of 130 I could write him as 130 I where I could write them as I 130 and they all mean the same thing okay now this is going way back like beginning of the year back but I want you guys to give me proton Neutron electron counts for each of these things now this shouldn’t be too tricky but I’ll walk you guys through the first one just in case this has kind of escaped you guys over time here so sulphur 34 the first thing I’m going to do is I’m going to go to my periodic table and find out his atomic number his atomic number is sixteen which tells me that he has 16 protons and since he’s not an eye on I’m going to assume he has 16 electrons to so this first numbers protons the second number is neutrons and the third number will be electrons now until unless told otherwise assume that all these atoms are neutral so protons and electrons are equal to each other now this is the mass 34 and I know that it’s made up of protons and neutrons together if 16 of the 34 protons then I know the remaining mass which is 18 has to be the neutrons that’s basically it I want you guys to try 17 18 and 19 on your own good luck all right well carbon that’s easy his first number is 6 his last number will also be 6 his total mass is 13 so he has to have seven neutrons barber these two together have to make up that mass all right let’s see Pluto neum this guy’s fun plutonium is going to have a atomic number of 94 which means he’ll have 94 electrons at the end and then if i subtract him out i get 150 neutrons he’s a really big guy so 9450 94 and then radon if I work him out becomes 86 136 and 86 again okay so here’s what this is all kind of leading up to I want you guys to be able to use this notation to show equations that involve nuclear radiation so we’re going to go over this much much much more in depth of future chapters here but I do want you guys to understand the basic idea so when something is unstable or when an atom is unstable it doesn’t have the right number of neutrons doesn’t have the right number of protons something heck maybe it has too much energy you guys remember from last chapter chapter too much iron tools they eject them the immune must more so there’s different ways to Adam can do this the first type is what we call alpha alpha radiation is when Adam that’s very large kicks off an entire chunk that’s nucleus so a massive Adam a very heavy atom kicks out a 4 over 2 alpha particle now if you guys remember that bottom number is the number of protons so really it’s just helium so basically it’s an atom I’m very large Adam kicking off a piece of

itself about the size of a helium nucleus and becoming smaller in the process so there are two ways you can write this for over 2 alpha which is kind of that fish symbol going on there or you can write it as for over to helium the mass of for two protons that’s what makes it helium this is also the largest of all the types of radiation which makes it the easiest to stop we’ll talk more about that in a second all right beta radiation now this is a very strange one but something you’ll have to understand is a neutrons actually made up of a proton and electron so what beta beta radiation is is a neutron breaking into two parts a Bray the basically the neutron breaks to give you a proton and electron and if we draw it out using a ZX notation it’ll look like this neutron has a mass of one but no charge it kicks off a proton which has a mass of one and a charge of one and it kicks off a mass of zero but a negative one charged electron this stuff’s actually fairly dangerous this stuff hits you it’s actually going to hurt pretty badly there are two symbols you’ll see use for this 0 over negative 1 e for electron or 0 over negative 1 beta which is the other symbol for this either symbol is acceptable just be aware that you can write it either way all right gamma this is actually the most dangerous because pretty much nothing can stop it now there’s no mass difference here all it is is a very high energy Adam giving off its energy in the form of a photon if you guys remember a photon is a particle of white so a gamma-ray think of the most intense laser in existence multiply that by about a trillion and you kind of get the idea a gamma ray is supposedly what created the Hulk in the comic books ya know a gamma ray vaporizes you now if you ever woke up pictures of what’s called the shadows of Hiroshima you can see what this does point-blank when a nuclear bomb goes off it vaporizes everything within several miles and by vaporizes I mean the atoms themselves don’t even survive so yeah you’re on to surviving this or about zero but anyway it’s a very high energy Adam giving off some of its energy in the form of incredibly high frequency lights and becoming a low energy Adam here’s what’s cool about this it’s the same Adam going in and going out the only difference between the two atoms is that this guy had a lot of energy this guy doesn’t the particle that kicks off has no mass and no charge which is why it’s impossible to stop this thing because it’s so small because it’s so incredibly powerful you can’t really stop gamma gamma is incredibly dangerous its symbol as zero over zero with a funny kind of why like symbol right here you’ll see this from time to time all right for those of you who are aware of this yes antimatter does actually exist so this time travel we talked about this a little bit back in chapter 3 as well positron is what’s called beta plus radiation so it’s essentially beta radiation but positive it’s an antimatter electron and this thing is actually traveling backwards in time which don’t even get me started on the side effects here but what’s weird is it’s an electron travelling backwards in time which makes its charge positive very very weird so essentially it’s a positive electron it still has the same mass which is basically nothing you just simply show it as a beta particle with the positive if you want to differentiate it between this and a normal electron but one way or another you need to make sure that if you ever mess with a positron its charge is a plus one its mass is zero and if you use the beta sand will remember to put the whole plus there now here’s the fun part this thing meets a normal-sized electron from our universe they go boom and it’s incredibly powerful all right the last one this is actually one of the most common is the idea of neutrons being ejected from the atom now if you guys remember neutrons are just kind of like the little shields that exists between the protons keeping them from repelling they’re kind of like the glue that holds the atom together in a way so these things can actually be absorbed or ejected from the atom during what are called fusion and fission reactions there are other processes that do this too but we’ll talk about those later fission is the splitting of large AB infusion is coming together as smaller ones we’ll talk about that a little more later but let’s say that a heavy isotope something with a lot of mass kicks off a neutron it becomes lighter that’s one way this can happen lighter isotope can absorb a neutron and become heavier and the symbol for this is massive 10 charge and the end for Neutron you’ll see this quite commonly now needless to say I’m just gonna tell you now you need to memorize these things you’re going to be seeing them a lot you’re going to get a lot of practice it’ll make this a lot faster if you take the time to study them a bit but that is just my advice all right now we need to talk about two things called shielding and penetration now you can

block radiation many different ways so alpha we talked about alpha being the largest it’s actually for over 2 alpha because of its incredibly large size compared to the others alpha can be stopped us by something as small as a sheet of paper alpha can be stopped by pretty much anything except air and even then after a couple of inches it really isn’t all that powerful at air either so back in the old days they actually had chunks of uranium sitting in labs and you could touch them is it recommended no but it’s not going to kill you outright because certain types of uranium only give off alpha radiation and your skin is actually thick enough to block it so alpha radiation actually isn’t dangerous unless you eat it now back at the Cold War there was an incident where a guy who defected to our side got stabbed with an umbrella with a piece of polonium which gives off alpha radiation inside your body alpha radiation havok outside can’t do much but it’s not the most friendly type of radiation either now beta and positron radiation are not blocked by paper at all they just go right on through it they’ll pass right through water and oil but they can be stopped by a sheet of metal now that’s basically the idea behind beta and positron radiation gamma goes through pretty much everything you can weaken gamma as it goes through heavy wet shielding and by heavy lead shielding I mean several feet of it but gamma penetrates pretty much all shielding with very little weakness and last but not least neutron radiation can actually be stopped by water and oil nuclear reactors give off a lot of the stuff which is why water is used to cool nuclear reactors the hydrogen and basically anything that contains a great deal of hydrogen can actually stop neutrons so whatever we dispose of nuclear waste we usually keep them in giant pools for water the water glows blue is the neutrons try to pass through it it’s called Cherenkov radiation anyway but this is how you stop the different types of radiation if you’ve got gamma on your hands good luck you’re really not going to stop it now gamma can’t be stopped all that much but x-rays are just stepped down this is why we can use x-rays to make a picture of your body they’re just a little bit less powerful than gamma so you can think of gamma as being a little bit stronger than x rays now here’s the deal with this you could take a picture of your body like an x-ray with a gamma ray you just die after the fact x-rays are a little less powerful and a little less dangerous so x rays compat are the version we use to take images at the inside of your body now if you’ve ever gotten an x-ray they cover your body or the parts of it that are not being X raised with that heavy heavy heavy you apron it’s full web powder the idea being that x-rays can be stopped by wed gamma just can’t so they’re very careful to make sure that the thing they use to take images of your body is not giving off gamma rays but it’s the stacked instead giving off x-rays so with that all said let’s talk about writing nuclear equations so this is what this is all kind of leading up to is the idea of writing an equation that involves nuclear change so the only difference here between normal stuff is that essentially what goes in does not have to come back out now be careful how you interpret this conservation of mass for the most part is maintained but just because polonium went into this reaction does not mean plenty and will come back out I’ll show you guys what I mean if you look at this reaction the total reactant side the mass on that side is 210 the particle that was kicked out had a massive for producing a particle that has a mass of 206 206 plus 4 on the product side makes a mass of 210 which matches the mass on the reactant side now the particle that got kicked out of this guy the alpha particle here or helium nucleus had two protons we started with 84 that means this guy can only have 80 two protons what goes in must come out kind of so the deal is you’re going to be balancing numbers across the top and across the bottom this has an interesting side effect for a lot of nuclear equations it means you can create a new element now the mass doesn’t decide what the element is but the charge the number of protons does this atom that we’ve created has a mat or a proton count of eighty two which makes it lead PB so how that you could interpret this is that Apollonia madam with the mass of 210 if it gives off an alpha particle becomes a lead atom with a mass of 206 what goes in must come out again kind of so here’s the idea let’s try 21 on our on our own here so what

came out had a mass of 236 one of the things that going in has a mass of one so something plus one gives me 2 36 this guy must be 235 now something plus 0 gives me the 92 so this guy was still element number 92 92 on the periodic table is uranium so all we’re seeing here is an isotope of uranium with a mass of 235 absorbing a neutron to become a heavier isotope same element different mass now all right I want you guys to try number 22 on your own see if you can figure this out okay well the thing that went in had a mass of 198 the thing that came out had a massive the heart 98 so whatever this is must have a mass of zero and 79 79 this guy has a charge of zero so I go flipping back and I’d look at my types of radiation because there’s nothing on the periodic table that would match this however the only type of radiation I know if that has zero over zero is gamma so this is an equation that involves a gamma ray being a minute so I show a little why there for gamma try number 23 on your own see if you can figure this one out ok so if I look at this what winton had a mass of 252 what came out had a massive 252 so the missing particle here has a mass of 0 99 went in but here’s what’s odd a hundred came out so if I put 0 here this won’t balance if I put a 1 here this won’t balance the only number I can put here is a negative 1 because negative 1 plus 100 makes 99 now again I’d foot back and I look at my types of radiation I need to know a particle that has a mass of about zero but a charge of negative 1 that would make this an electron or a beta particle you could write it either way the other possible answer here again would be 0 negative 1 e they both mean the same thing okay trout number is 24 and 25 on your own keep mind these are a little bit more involved just pay attention to what the mass is on the reactants and other products do the same for the protons so they’re really just kind of like puzzles I’ve got a mass of eight entering I’ve got a massive one exiting so to make up the difference this guy must have a mass of seven I’ve got a total of three protons coming in but none coming out so this guy has all three protons I go to my periodic table I woke up who element number three is its lithium and we’re done I go down to this one right here now it’s something going in and all of this coming out so I’m going to look up on the top 1 plus 64 plus 1 22 so this is actually a fairly large atom here if I’m looking at this and I should get a mass of 187 here if I do the same thing along the bottom I get 79 protons and element number 79 is gold which is a you so what goes in must come out just again kind of so 187 should match all three of these put together it does the 79 should equal all three of these put together which it does so if you haven’t kind of guessed this type of radiation actually makes new elements all these types of radiation do except for gamma now let’s talk about doing this in word format so if you hear the terms capture absorb or undergoes it usually implies the things that we’re talking about our reactants if you hear emits emission release or eject it means that something is most likely a product so 68 ZN emits okay this guy is doing the job so he’s probably going to be a reactant he’s emitting an alpha particle which makes it a product and the thing that’s forming is probably also a product so I’m going to show 68 over the atomic number for zinc which is going to be 30 ZN emits so it’s going to give off an alpha particle so for over 2 alpha plus a product that I don’t know so I know that came in with a mass of 68 so this would have to be 64 this guy came in with a math or 30 protons two of which had been kicked out so this to balance it would have to be 28 if i go to my periodic table now woke up l number 28 this is nikhil all rights so something i don’t know so this guy is my reactant absorbs a neutron which is remember absorbing makes it a reactant

and it forms this guy which is a product so I’ve got something now oxygen no varnish so bring post-war get some teams of 16 and something plus 0 gives me 8 so 8 and this is oxygen so oxygen 16 Oh 16s whatever you want to call it all right your turn 28-29 try these on your own ok cobalt-60 is ejecting the positron that makes this a product and whatever it produced is also a product cobalt-60 is the thing all doing this so this is a reactant so I’ve got 60 Cobalts ejecting a positron which is 0 positive 1 beta plus to produce something I don’t know to fill in the blanks I’m going to go to my periodic table cobalt has an atomic number 27 k60 lose 0 still 6027 lose a positive that makes this 26 I’ll go to my periodic table again this is going to be iron iron 60 all right so something forms k40 by beta emission so all this chunk right here is product this guy’s my reactant so I’m looking for him he’s going to kick off a 40 over something k and he’s emitting a beta particle so 0 negative 1 beta as well so i go to my periodic table this is 19 I’ll do my little bit of math here this should be 40 and this ends up being 18 to balance it element number 18 is argon and you’re done all right last set try some of these on your own we’ll start with 30 and 31 okay the Li 6 is doing all this so he’s a reactant he captures an electron capture as a reactant thing again the thing he’s forming is a product so I’ve got six over something with him capturing a 0 negative 1 electron to form something I don’t know so if I complete this at six over three with him he’s capturing something with a mass of zero so his mass is still 6 3 plus negative one gives me two element number two would be helium so helium 686 whatever you want call it all right 31 fermium 256 undergoes alpha mission well alpha is being kicked out so that makes this thing a product and this guy obviously did it so he’s a reactant so I’m clearly missing something here I don’t know what it is so i’m going to write what I do have 256 and the symbol for fermium is FM fermium has an atomic number of 100 he’s kicking out an alpha particle so for over 2 alpha or you could write as furrowed over to a qi plus and the thing is it’s pretty clear where I’m missing something I’m missing something on the product side here whatever that has to be is 252 over 98 I’ll go to my periodic table element number 98 Louise a big one that would be californium C F all right numbers 32 33 and 34 you’re on your own with this one give it a try all right here we go okay so this is a larger one this guy’s doing something so he’s absorbing a neutron so I’m going to show 10 B II absorbing a neutron which is 10 n he’s emitting a beta particle so giving it off 0 negative 1 beta to form something I don’t know so if I complete this if I’m using really emits 10 / for beryllium so if i do my mass is I’ve got 11 going in 0 going out this has to be 11 to balance it for going in negative 1 coming out if I put a forward here this side equals 3 that’s not going to work so this has to be a 5 and the element number 5 is boron be very careful to make sure that you don’t put a tail on this thing when you ride the symbol for be because of be with the tail as you guys know is beta all right number 33 this is easy so something I don’t know releases a gamma ray 0 / 0 gamma to form 184 / something tungsten which is w

tungsten has an atomic number of 74 here’s the deal the particle I kicked off had nothing so it’s the original Adam 104 84 / 74 tungsten our gamma rays don’t change anything in the atom just its energy all right last but not least example 34 all right iridium 190 captures a neutron and emits so up to here this is all reactants and then the rest of this is all products so iridium 190 which is ir 190 captures a neutron so 10 n to emit an alpha particle and something else that I don’t know so if i go to my periodic table iridium has an atomic number of 77 so total mass going in is 191 four of which has already come out so to balance it this has to be 180 777 protons in two came out this has to be the remaining 75 I go to my periodic table this is rhenium r e there you go alright if you got all this on your own your sets I wish you guys the best of luck a quick hint on the practice that questions for now when you guys are working these problems just to answer them in the format’s I’ve shown you when you guys do the practice that it’ll be very specific how it wants you to write these in it may ask you to write it like this it may ask you to write them like this hack it may ask you guys to write them like KR 84 or something like that just pay attention to how the problem wants you to answer the name and that’s it I wish you guys the best of all