Nuclei with the same number of neutrons but different mass
number...

Question

Nuclei with the same number of neutrons but different mass
numbers are called isotones. Write the symbols of four isotones
of 236Th.

Accepted Answer

Hey everyone in this example we're told that two nuclear sites are ice atones. If they have the same number of neutrons but different number of protons, they want us to identify four ice atone symbols for 233 pro tacked any. Um So we want to focus on the f block of our Act tonight series group number in our periodic tables. We also want to recall the fact that the represents in our isotope symbol. So let's actually just outline our isotope symbol. First we have X representing our protect any. Um here a representing our mass number and Z representing our atomic number. We want to recall that Z. And a neutral atom only will represent our atomic number as well as our number of protons. And we also want to recall that a represents our mass number and we can find that from taking our number of neutrons plus our number of protons. So what we want to do is find Our z. value for 233 protect any. Um When we look at our periodic tables we see that Z corresponds to 91 for protect any. Um and therefore we would conclude since our isotope is a neutral atom here of protect any. Um we have then 91 protons. Next we want to go ahead and figure out our number of neutrons. So what we would find is we have our atomic mass which is given to us in our chemical symbol for protecting me. Um Our atomic mass is given as 2 33. And we're going to subtract this from our number of protons above which we just found as protons. So this difference gives us a value of 142. And so we have 142 neutrons in our protect any um isotope. So to write our four ice atone symbols, we want to pick four adjacent elements near our protect any um on our periodic tables. So if we go to Adams to the left, will land on a C. Representing Act any. Um And we would determine that our atomic number for a titanium Act any. Um sorry on our periodic tables equals 89. Because we're trying to write out a ice atone. We want to keep the number of neutrons the same. So we would say that N. is equal to what we found above for our number of neutrons for protect any um being 142. So we just need to write out our mass number for this isotope of Act any. Um And because we found our atomic number and our number of neutrons we can say that therefore our mass number is equal to 89. Our atomic number for Act any um plus 1 42 are number of neutrons in Act any. Um And this gives us a value of 2:31. And so we can say that our ice atone symbol Is going to be 2:31. Act any um A C. So this is our first ice atone symbol here for Act any. Um Which is the adjacent atom two elements to the left of our protect any. Um Moving forth we want to go and look next to the right of our Act any. Um And we will we will run into thorium T. H. So looking at thorium we would see that we have an atomic number equaled in 90. And again because this is an ice atone symbol, we want to keep the number of neutrons the same. So we would say n. 142 keeping things consistent. So we would say that therefore our mass number for our thorium is going to equal Our Z. value. Which we found as 90 for atomic number of thorium from the periodic table Plus our 142 neutrons that we have been keeping consistent in each of our ice atones. And this equals a total of 232. Where we can now write our ice atone symbol to T. H. So this is our second answer and second ice atone symbol. So now we want to go ahead and go back to our protect any. Um and go to Adams to the right of our protect any. Um And we would land on. Sorry we would land on N. P. And let me just get rid of that highlight for Neptune Ium. Now when we look at our atomic number for an activity napped any. Um our Z. value for atomic number is going to equal 93. And again we keep the number of neutrons the same. So N. Is equal to 1 42. So therefore we would say that our atomic mass of our Neptune iem is equal to 93 plus 1 42. Equaling a total of 2 35. And so we would say that our symbol Ice Atone symbol for Neptune Iem is going to equal to 35 N. P. And this is our third ice atone so far in our third answer. And next we're going to go ahead and Go one Adam to the right away from our protect any um and we land on uranium. So we would get a atomic number of uranium from the periodic table of 92. We keep our number of neutrons consistent as 1.42. And we get that therefore our atomic mass or mass number is going to equal 92 plus 1 42 which equals 24 for uranium. And so we would have to 24. Oops We would have to 24 You for our 4th ice atone symbol. And so everything boxed in blue represents our four ice atone symbols which are produced from our original isotope Protecting 2 33 protect any um here. So I hope that everything we reviewed was clear. If you have any questions, please leave them down below. And I will see everyone in the next practice video.

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