Nuclear Half Life: Intro and Explanation
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- Опубликовано: 18 сен 2024
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Nuclear half life is the time that it takes for one half of a radioactive sample to decay. In this video, we will learn the basics of nuclear half life, and examine graphs and practice problems.
Great questions!
1) It always decays by half, whether you have 80 grams, 10 grams, 4 nanograms, or 2 atoms.
2) When you're down to only one atom left, that one atom is eventually going to decay into the new atom, and then you won't have a single atom left of the old stuff. So you're not going to have half an atom decay, it's all or nothing.
If individually each atom of said element is unstable and wants to decay. What makes 1/2 atoms wait for the other half to decay during the duration of a half life? why don't they all decay at the same time?
@@yashasthana1157 great question.!
What I think is happening there is when atoms decay they release particles that turn back some of the decayed atoms into the old stuff by attaching to new decayed nucleus to keep the overall decay rate constant....what do you think? what I meant was the last atom left in the mass would decay immediately and wouldn't take the same half life to decay. concept of half life fails when we have countable atoms...
@@yashasthana1157 , It is based on mathematical probability,... so like a roll of the dice. The overall half life is not totally predictable on an atom by atom basis, and though statistically half of the elemental sample has decayed after the period of the half life is complete, You cannot tell on which day, hour, minute, or second anyone of those atoms will decay.
I have a question if a radioactive nuclide has a huge half life does that mean it's less radioactive when compared to a nuclide which has shorter half life ?
Bravo to you Tyler ... your energy in explaining the concept was superb ... unfortunately I grew up in era where a lot of the professors were quite boring ... almost as if they were reluctant to share the information. People like you give hope for the younger generations. Wish more of your group would use RUclips to obtain useful information like this. Thanks.
50% of people actually know about nuclear half-lives
The other 50% plays Half-Life
Quietbut_Deadly Well the thing is I knew the game probably got its name from something in science I just didn't know what it was XD
***** lol I don't know
I liked the fact that you used capitals in the game's name
I'm from the latter 50%... Could not stop thinking about it when it came out in class.
what about those of us that just do it because we wanna get a good grade on our math hw?
Someone: hey have you heard of half-life?
Me: half-life 1 or 2?
Someone: what?
Me: what?
Honestly I can’t watch Crash Course.... It’s boring and hard to understand. When I found this channel though, I can now actually learn something without being board or confused. Thank you
bored*
Thanks, I am in the UK and this has helped me so much. I just wanted to let you know that you are helping people learn all around the world, and frankly you have taught me in 5 minutes what two of my physics teachers couldn't in 5 weeks.
Wonderful representations! I have been confused by my teachers about this concept for a year and even before the exam I still didn't understand that! You are such a genius
I just came here for Half Life and my mission to find Gman
*Gordon Freeman!*
Where ever you are now sir. I hope everything is good and know you made my chemistry class way easier. Straight Legend!!! 💪🏻🔥🎉
Agree!! This makes soo much more sense then my teacher explanation
Bro the way you explain this is beautiful
Your videos are amazing. You are a teacher by birth I would say! Thank you!
Nuclear half life tells us how long does it takes for half life 3 gets release
Red Guy is my life
4.5 billion years to half-life 3
Half Life 3 confirmed.
yah. ha ha, now if only it were in three minutes.
+Archer R 3 LIKES???////???
half life confirmed doofy
There can only be 2 halves.. think about it
The ammount of time it will take for uranium 238's half life is how long half life 3 will be in development.
That's true, but I'm only talking about a specific isotopes of Thorium here, Th-234. There are other isotopes of Thorium that have much longer half-lives, up to 14 billion years. So there might not be any Thorium-234 around, but there is plenty of the other types of Thorium. Great question!
Tyler you make awesome videos!!!!!! these are extremely helpful for me in my chemistry classes. I've learned more from your videos than my instructors lectures
You are my half life,You saved me during my exams hours🧐
God Everywhere if you stop using your phone u gonna understand teacher in class-room .
I was SO LOST without your videos when it came to "solutions and equilibrium" :(
Great video. You deserve much more than 300,000. just fully underrated content. Thanks again :-)
I say keep the paper Tyler. I love the creativity you use and it Is very helpful towards my learning of chemistry
How do we know how long each reactions take? You're video is great but I really don't know how you just knew that Th to Pa has a half life of 24 days, or how you knew U to Th has a half life of 4.5 billions year, etc...
+Ashtin Petitt Great questions. Scientists have already figured out those numbers. You can look them up in books or on the Internet.
+Tyler DeWitt yes but how did the scientists figure out those numbers?
+Fraser Wyllie the magic man in the sky told them
+Ashtin Petitt, its enough to watch it for short period of time and count the number of atoms that have decayed, and from there you can calculate the lifetime and half-life. all you need to know is the initial number of total atoms in sample and the number of atoms that has decayed during time t. for uranium 238 example, if this time t is even several minutes it will give good estimate of lifetime and half-life. needless to say, the bigger this time t is, and the more atoms you have in sample, the better estimate will be.
+Ashtin Petitt en.wikipedia.org/wiki/Half-life
you can see the formula of (t1/2 ) here :D
Dude ur videos are extremely helpful much appreciation!
The best ever teacher. I m watching this video in 2024 and i've learnt from it.
Tyler making the complicated simple AND not making me feel like a dummy. Thanks Man!
Very educational! Thank you so much for educating us about this very tough subject. I learned more than from my science teacher 😆
WOW!! Thanks for the explanation!!
Well explained, i never understood what half life was when they taught in schools, now after watching this video i understand it more precisely and think this is so easy, wish our teachers taught all this just like you!
Hi. I did chemistry along with microbiology over the summer, so I missed alot of the concepts in chemistry because I focused more on micro. Watching your videos has done wonders for me, very straight and easy to understand.
You're so helpful man ! Thank you so much ! I wish you were my teacher !!!!
but since you can always divide a number by two and it'll never be zero- does that mean a sample can never be 100% converted?
also- am i understanding correctly that it takes the same amount of time for a 3 million tons sample to turn into a 1.5 million tons as it does for a 2g sample of the same element to turn into 1g?
I want to know why only half the sample decays at a time, why not the whole sample like logic is telling me? It’s like time stops for 1/2 of a whole.
@@mynameisralfbob2276 because the nuclei can never decay to zero, atleast that's what I think. That's why when you draw the graphs, it will never touch zero because it can't decay to zero. And other numbers could get hard to work with, keeping it simple is 1/2.
I get how half life works, I don't understand WHY. The question I have is why does exactly half of the material decay, why is the rate not constant or random? What is the reason for a very orderly exponential rate of change?
Umenemo
That is how nature revealed itself to us. All things decay the same way, in relation to their own selves. A=P(1+1/i)^n , the larger the value of i is, you see that the value of A becomes e. No matter what you do, it's always almost equal to e. Things decay in relation to their own size. Half life is a method derived to understand of how things decay, the pattern is the same no matter what and where in time and space as we know. Why, we don't know, that is how it is, it's a pattern and never disproved, perhaps the next Nobel prize if someone can find a way to break the pattern for some matter in some part of the universe.
It's so perfect how the videos you are uploading are helping my review for my chem 102 final!
This would basically be more of a physics video, but Chemistry and Physics have much in common. Great videos, my friend.
This Is A Simplistic And Comprehensible Explanation Of Half-Life. Thank You For Your Clarity, I Was Having Quite A Bit Of Difficulty With This Previously.
Its 2020 and today we were learning it mu teacher said: so class do you know anything about half-lives.
I was like: Ya it is an awesome game I played both of it
The whole class started laughing and making jokes
And the teacher got me out of class and now i am here
Noice
I got 24 days because I looked it up. Each element that does radioactive decay has a different half life: some are a few seconds, others are thousands of years. There's no way to know what the half life will be unless sometime tells you. And you can definitely go beyond 10: 5, 2.5, 1.25, etc. etc. it cuts in half every time. Does that make sense?
Love the video. Are you still active on this channel? There has to be some way to calculate !/2 life of elements because they are published, and no one has been around for 4.5 billion years, although i guess with a few years of observation one could calculate 1/2 life even for long half lives, by the rate of radioactive decay.
I was also going to point out that You are leaving out the first "T" in the name of element 59 Pro"T"actinium. thought I'd be proactive on that. Could You also do a video about what causes the different kinds of decay. and why half keeps disappearing probabilistically rather than linearly ?
Gordon doesn't need to hear about that, he's a trained professional!
I got that reference!
The best person to explain Chemistry, thank you 🥰🥰
You explain it so well, thanks for clearing things up before my physics test tomorrow.
BRuhh and we took a week to learn thus.
BTW yall doin this for your exam as well ;)
good luck...
So I have a couple questions:
1: So no matter the sample size always half of it will decay in the half-life time? Whether the sample is 80 grams or just 2 atoms?
2: If we had only 1 atom as the sample size, how long would it take to decay? How could only half of an atom decay or is it just the whole atom and this sample size breaks the rule.
It would be great if you could answer these for me! Thanks for the awesome video, I'm in grade 10 and I'm watching these to learn grade 11 material early.
How can anyone not understand this after you've explained it so well? Seriously, some high school teachers these days need to take a page from your book.
this helped me sooooo much on my test. Thank You!!
I learn more from you than my own physics lecture lol
We all appreciate what you do.
Thanks bro, I wanna know one more thing, will concentration play a role here? I mean in chemical kinetics we have studied about zero order and first order reactions and about how some of them are dependent upon initial concentration of the reactants and as the amount of reactants decrease, the rate if the reaction also decreases, will this be the case in these Nuclear Reactions too? Although I know you haven't shown the reaction's rate's dependence upon concentration, but still I don't know why its bothering me. Thanks in advance.
U are my best online tutor
The thing about this process that I'm trying to wrap my head around.... So the reason we quantify the decay in half-lives, is because all these decay rates are constantly changing, right? The decay rate isn't constant, otherwise after 48 days you'd have NO Thorium instead of 20 grams. Second by second, the decay rate is actually slowing down, which would require a different calculation, so we put it in terms of half-lives so it's easier to understand and portray....right?
Hi +Tyler Dewitt sir, your videos are amazingly helpful, but I just have slight concern about what if we don't know the half life or an element, then how do we solve?
Eg. After 24.0 days, 2.00 milligrams of an original 128.0 milligram sample remain. What is the half-life of the sample? How do we solve such a question? Pls help sir.
You estimate the power of two that brings you from 2 to 128,...i E the inverse of the 1/2 power, which gives You 7 ... 2x2=4 4x2=8,,...etc 2 to the 7th =128 , You subtract one because at the end of the 1st period we are already losing 1/2, so 64 mg after the 1st halving. So we a re left with 1 over 2 to the seventh after 6 periods. So if You start with 128 and are ending up with 2 milligrams, the 1/2 life would be 4 days. because 6 goes into 24 days to equal 4 days. IE after 4 days you have 64 mg, after 8 days=32, 12 days 16mg, 16 days= 8 gms. 20 days=4 gms, and 24 days = 2 mgs.
I know,... pragmatic math is tricky even when it seems pretty simple.
@@Geopholus bro you answered my 6yr old high school question… don’t remember what I did or how I did it but like it’s funny that I’m getting a reply now but like thanks bro
@@laralara6607 Yeah I figured You long ago finished that class. 50 years later i still remember what i learned about 1/2 lifes of isotopes from High School. Too bad no one has ever figured out that no civilization will keep nuclear waste safe for 4.6 billion years !
Thank you so much I am studying for my physics exam and I desperately need to learn half life as my revision booklet wasn’t helping.Very helpful once again thank you
you saved my life, one video at a time XD
you are the best than all teachers I had
thank you so much! i got really confused with this when my teacher explained it, but watching how you did it really helped. Thanks a ton!!!
A clairifcation please. Everything is VERY clear and beautifully explained except that at the very beginning you are talking about how THROINIUM 234 has 90 protons. But then you jump to saying that 1 of its NEUTRONS changes to a PROTON, changing THORINIUM 234 to PROACTINIUM 234. If that is accurate then why didn't you begin by saying something like, "So, THORINIUM 234 has 90 protons and "x" neutrons. If one those neutrons should change to a proton, THROINIUM 234 also changes to PROACTINIUM 234." I hope my confusion is clear. I'm 78. I've been trying to understand half-life ALL my life. I'm finally almost there!! I will greatly appreciate your clarification on this.
You made it quite easy to understand Half life. Great work!!!!!!!!!!!!!!
Thank you so much. the way you explained the process was very clear bub and I think this the first time I got the right idea of the process right.Thank you!
congracts on a million subscribers.
i am that one in a million 🤩
Thanks!, Because Of Your Video I Was Able To Make It Into M.I.T.
To make a PHD in Nuclear physics?
Thank you for the clear and simple explanation!
Why are you all arguing about paper, it's all about the video and whether its helpful or not, Tyler just ignore him and teach the way u do it cuz its the best way
Your ways of teachers is awesome...hat's off
Thanks! This really helped me a lot for my HS chem class. I can tell you enjoy teaching.
I was wondering why only half of the sample decays, what decides which atoms decay and which don't and was that stat an average or does exactly half the sample decay? Ty for the video
I don't understand, does this mean it willinfinite amount of time for something to decay completely??just asking.
no, it will never decay completely.
Thanks man. I got test tommorow and I had no idea about this stuff.
your videos are easily better than khan academy like by miles i can understand yours so much better
Thanks for an actual explanation instead of one that goes like 'half life is... half' like what even it's like some people think you already know what it is xD
Thanks for the very detailed and clear explanation!
Thanks Sir you made me to understand each and every line
This video is awesome. I was having trouble understanding half-life but this video made it all clear to me. Thanks 😀
Wow. These videos explain stuff so much better than my science teacher. Could you please do one on carbon cycling? The teacher is driveling on about it using lots of decipherable jargon. I'm sure you would be able to make it much clearer!
Fantastic vid but u wrote the atomic weights of Pa, Th,Po wrong
decay? half-life?
half life decay confirmed
Can you please make a Gamma Decay video? You explain these concepts so clearly and well.
Its Protactinium by the way lol, not trying to be mean its just my OCD and great videos man I understand Nuclear Fission, Half-Lives, and science cause of you thanks for the videos! :)
Ur the best chemistry teacher
The pre-made cards are appreciated.
Thank you!!! you make it very easy to understand. I am going for a health physics test
Polonium turns into lead in 3 minutes.
My question, where do you find polonium if it turns into lead this quick.
So all polonium should be lead because the earth is older than 3 min?
Im so curious about this stuff.
Polonium is not a stable element (no stable isotopes) therefore it exists in small quantities that get turned into lead quickly.. Also bear in mind that Polonium is sometimes the Products/byproducts of nuclear decays/reactions
+SpartanCreeper T It also depends on how much Polonium is present in the decay process, as stated in the video😀
I think the idea of decay somehow fails when you start with 80 atoms of Thorium instead of 80 Grams. What happens to the last atom? Or say what prevents the other half atoms from decaying in the same 24 days the other half decayed. So think the presence of other atoms around an atom is whats inducing the decay. Would you agree?
so if you have a certain amount of thorium, it will never disappear because only half of the amount decays over any length of time? that doesn't seem right since it would mean that after half of some arbitrary amount of thorium is gone, the rate of decay magically changes at that instant for the next half life period..A fixed decay rate or decay rate curve over time makes more sense..what am i missing here?
Thank you so so much, I'm subscribing. This video was great.Continue to make them please...
You are amazing!!!!!!!!!!!!! Thank you for all your youtube posts!
best teacher ever thank youuuuuu
Good video, but use white board with marker in future, you will save a lotta paper !!
Thanks for the comment. I can't use a whiteboard because the shiny surface causes a reflection that makes it very difficult to see the writing. And the amount of paper I use is tiny: maybe 10 or 20 sheets in this video, which is viewed tens of thousands of times. When a teacher photocopies a test for all of their students, that is literally hundreds and hundreds of sheets of paper every day.
+Chandraprakash G Um, I think you're under the mistaken impression that every time someone views this video another piece of paper was used. Tyler is not using a new piece of paper every time the video is viewed. This isn't actually live; Tyler just did this once, and by the magic of those beta rays (electrons) speeding around our computers, you are watching what he did . . . three years later! Tyler is an old man now!
greg55666
Actually if the lights are placed in correct angles, the glaring problem in white board would be reduced, also there are Matte boards which avoids that glaring problems.
Tyler does have around 100's (10's of sheets for a video) of videos, so all what i said is if white board markers are used, that too with refillable marker inks, even in a month time, he could save 100's of papers.
I am not accusing Tyler, all i said is, it would be just an better alternative, thats all.
I don't think going green is a bad idea.
+Chandraprakash G Just shut up. When Tyler said "I can't: glare" you should have said, "oh I see, I didn't think about that." There's nothing worse than someone who is shown to be wrong, then tries to cover their tracks by being even worse.
LOL, in your view wasting paper is better than using white board !!
Can't help it, you have your view and i'll have mine.
Also at 0:30, shouldn't there be a presence of antineutrinos also? Because neutron-proton conversion (or Beta minus decay) gives an energy packet called antineutrino... Please rectify...
Great Job at explaining
very nicely explained!
Thanks a lot sir this would help me someday...I'm just curious at half-life process.
I have a doubt at 0:30 ... since thorium has a neutron-proton ratio of 1.6, it is unstable (since a large nucleus requires a proton-neutron ratio between 2 and 2.5 to be stable). Therefore, it must increase its neutron-proton ratio. Therefore, it must undergo proton-neutron conversion right? (and not neutron-proton conversion?)
this is amazing video....thank u so much sir.....
but also try to explain the rate decay because most students are confused to understand just like me.....😊😊😊😊😊😊
232 thorium + one neutron = thorium 233 to 233 protactinium 22 minutes to uranium 233 27 days.
Great video! My only note, check the spelling/pronunciation of element PA.
Is there a "trigger" for the decay? or if it just happens automatically, the universe has been around for 13.8 billion years; wouldn't most of the decaying be completed already?
great work . thanks for numerous effort
during nuclear decay neutrons turn into protons? so you could actually plus charge any neutron or not in a lab? if so can you also negatively charge a neutron turning it into an anti proton?
Thank you so much. You have replaced my science teacher XD
omg this is amazing... i don't comment too much on videos but I have to comment on this one. thank you so much for this sir❤
very good video to understand Half Life!
are the neutrons responsible for the atoms being susceptible to the earths gravity?
and does the proton have anything to do with making things lighter?(for instance in helium)
11 years later this vid is helpfull 😊