Nuclear Chemistry: Crash Course Chemistry #38
Вставка
- Опубліковано 10 лис 2013
- In this episode, Hank welcomes you to the new age, to the new age, welcome to the new age. Here he'll talk about transmutation among elements, isotopes, calculating half-life, radioactive decay, and spontaneous fission.
Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!
Download it here for Apple Devices: apple.co/3d4eyZo
Download it here for Android Devices: bit.ly/2SrDulJ
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Table of Contents
Radioactivity
Transmutation Among Elements and Isotopes
Calculating Half-Life
Radioactive Decay
Spontaneous Fission
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Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!
Download it here for Apple Devices: apple.co/3d4eyZo
Download it here for Android Devices: bit.ly/2SrDulJ
spicy air
k
All hail Crash Course. Please don't stop making videos at least until I'm out of high school.
graduate yet?
graduate yet?
crazy to think ur out already. i’m a sophomore smh
@@nicole4502 junior
Why are you learning about this in high school? Lol
You've taught my classes more than my teachers
+️Gay Ships are Yay Ships My chem teacher isn't even in the room half of the time, and when she is she doesn't even teach. she gives us worksheets and yells at us for not doing our work when we don't even know how to do it.
ayyy same lmao
Sir, you are absolutely COR-RECT
Nm
Homosexuality My Dear Watson
Thought someone was gonna say that. Though it is true...
Nuclear physicist here, two quibbles with your video. First a small one : at 6:21 you say that beta decay has "higher energy" that alpha decay -- It hasn't. It does have higher range, or ability to penetrate matter, which is due to the electron being 8000 times lighter, and faster than an alpha for roughly the same energy. Second: GAMMA RADIATION IS NOT CAUSED BY ELECTRONS but by changes in the internal state of the nucleus (protons and neutrons jumping shells much as electrons do to emit light). X-rays can be emitted by core electrons following electron capture decay by the nucleus, but that's different and a very specific process. Gammas are emitted by the nucleus. It would be nice to correct this vid, to keep it up to the standard of previous ones. Thanks !
Fascinating to see a nuclear physicist, I’m only an 8th grader working on a nuclear chemistry project lol
K
You probably cringe at fallout lol
@@twistiicuber1055 Im 12 in 7th grade, I'm just interested in this because it seems cool, which it is.
@Loading_101 cool
6:54 An error: Xe is element 54. Element 91 is Protactinium, which has an average mass of 231.03588 g/mol, which means that Pa-234 is an isotope which is heavier than average (meaning I suspect it will pretty soon decay as well).
if you think about it, radioactivity is just...
*S P I C Y A I R*
@MAHALAKSHMI PERUMAL why thank you.
this is the greatest thing ive ever read
You made me laugh so hard! Thank you!
@@uniqhnd23 Does it count that I'm dead *inside?*
wowzers
This is awesome. More evidence that we are living in exponential and information rich times. Keep the knowledge coming!
Not only have all of these awesome chemistry videos caused me to fall in love with Hank, but they have also effectively prepared me for my chemistry semester final! THANK YOU CRASH COURSE!
I've been hoping we would cover nuclear chemistry!!! This is my all time favorite topic. Nuclear pharmacy is like my dream job.
As a Materials Scientist/Engineer, I just want to tell you how much I love these videos. They're so fun. Keep it up, Hank, the signed poster I got from Subbable goes up on the wall as soon as I can find a good frame!
Thank you for your great work! This is my go to channel for any chemistry subjects I need help with. I really enjoy your random dry humor it definitely helps me stay attentive! Keep it up!
DID SOMEONE SAY HALF-LIFE!?
yes half-life refers to the time it takes for an element to reach half of it's lifespan
an g I don't think you got the reference
A HALF-LIFE OF 3 SECONDS?
halflife 3 confirmed
Lord GabeN Lord Gaben, enlighten us by Confirming Half life 3.
Gamma rays can occur from pure nuclear state transitions without involving electrons at all, when one isomer decays into a more stable one. Generally we talk about Gamma rays only when there's some sort of nuclear process taking place and X-rays when the process involves electrons.
True. Electrons giving off gamma photons aren't exactly something you hear when you learn about gamma radiation. Nucleus does that job.
It's true, electron transitions simply do not come in big enough energy intervals to emit gamma rays. A 6s->1s transition in Barium emits an x-ray 20 times less energetic than the gamma ray emitted by the nucleus associated with the 137Cs->137Ba beta decay
Gamma rays are not generated by transition between electron levels.
The energy difference is too small.
Instead, they are generated by re-arrangement of protons and neutrons within the neucleus. They frequently modeled by shell model, too, although very different form the electric one.
These videos are just amazing. I've been amusing myself quite a long time now with binge-watching Crash Courses on all kinds of subjects. It truly answers a lot of interesting questions that don't get enough attention in class!
This topic is not easy to process and for him to talk that fast makes it even harder to comprehend.
Love the Imagine Dragons reference!
When your teacher just asigns videos for you to watch during online school and you break your computer because the video is worse than your actual teacher
He didn't say Nucular. I'm so happy.
Omg I just happened to need this for next Monday's task!:O THANKS!
So, the half-life of Bismuth is 7.7 Septillion years. (7,700,000,000,000,000,000,000,000)
BRUUUUUHHHH
Slow down man.. I can't keep up.
This is the branch of chemistry that I find the most exciting.
This was awesome, I think I finally starting to understand Nuclear Chemistry.
At 6:53, how come it Xenon has a number of 91 when Thorium had 90 and when it released it's electron?
+Vishvak Seenichamy
i think it should be Protactinium (Pa) because thats number 91.
+Vishvak Seenichamy no no no a neutron turns itself into a proton releasing an electron
+Vishvak Seenichamy
There's actually an electron antineutrino wasn't shown in the beta decay equation.
When the thorium atom decays, one neutron in the nucleus converts into a proton, an electron and an antineutrino. Hence after the decay the number of proton increases (the thorium atom turns into xenon atom) while the nucleon number stays the same (number of neutron reduces by 1).
+Raito Ng I find it a neccesity to correct the typo here. It says "One proton in the nucleus", but I know you meant "One neutron in the nucles converts into..". This was so that people reading your comment will be able to understand what was wrong and what's right. :)
EDIT:
According to this information the atomic number should increase by one from the original atomic number. So it should increase from Thorium-234 to Proctactinium-234. This is because the protons increase by 1 and 90+1=91, and the atom with 91 protons is Proctactinium and not Xenon. This was probably just a typo from the guys who made the video and they probably just forgot to do something about it. xD
Didn't realize it. Thanks a lot xP
Please do Crash Course Physics!
Hole. y. Shit. YES!!!!
+Random Tech Videos You could go to khan academy
they have one now
+Random Tech Videos It just did *TODAY* FINALLY YES!!!!!!!!!!!!!!!!!!!
Random Tech Videos that would be sho helpful
nice editing dude! loved the video, learnt a lot, taught me more than my old teacher, Thanks!
this guy knows everything
Omg. I've finally seen someone make a reference to the Mutant Zombie from Minecraft!
I literally just had a chemistry exam about this on Friday... this would been so helpful! ._.
I love radioactive!
And nice minecraft reference.
I love how this simplifies otherwise complex information, schools need to be taught like this
In the nuclear industry and in school, they use californium-252 as a neutron source. Never seen 254Cf...
Also, although you can excite electrons into the energy ranges of nuclear gamma radiation (and vice versa), gamma rays are pretty generally a nuclear phenomenon.
I appreciate this episode, but it would really be worth doing over a few segments.
Thank you for making it seem way less crazy when I tell my coworkers that I learned how to make yellow cake at home. :)
Literally just about to write a paper about Arsenic 74. This really helped me understand the concept of nuclear chemistry! Thank you!
Just want to say I've watched most of these videos for my ap test tomorrow and watching these has been most helpful.
Hello mr.Green,
Could you make some videos about volcanos, earthquakes etc when you finish the chemistry? It'd be very helpful, you're a very good teacher. Greetings from Italy.
🎲🌋
dude you're incredibly helpful but talk so so so fast I can't process what you're saying.
put it at 0.5 speed
putting it at 2 speed is hilarious
I put it at 1.25 so i can understand xD
I had the same problem but 0.5 speed is too slow so put it 0.75 speed
hahahah
@ 3:40
"Hello Gordon!"
This was awesome, thanks!
HANK mentioned Imagine dragons!!! my life is complete.
Perhaps a video of the industrial uses, and the types of sources used would be a good idea.
you're so helpful... My chemistry grade has gone up since I been watching your videos ... you rock!
Gamma radiation is released directly from the nucleus, not from excited electrons. It's called ionizing radiation for a reason - a gamma ray is powerful enough to knock any electron out of the atom entirely.
Do Crash Course quantum physics/mechanics!
Too controversial
Hi guys, I love the videos! One issue is you're not on the mark for gamma decay. This is similar to excited electronic state de-excitation but it is actually nuclear energy levels of protons or neutrons falling to the ground state in the nucleus. I am a professor of nuclear chemistry btw
I am very thankful for your help. Now i totally understand this!!
I love Crash Course....all videos are fun and perfect....Love it.
I had a test on this on friday, looked everywhere for a radioactivity video and of course its posted just 3 short days later -_-
Recommendations for watching crash course:
1. Take notes when you watch the video
2. Pause the video and replay if you don't understand something
3. Set the speed to 0.75. This makes it much easier to understand
That intro was the single best thing I have ever seen or imagined seeing ever
0:09 WHOA-OH OH I’M, WHOA-OH OH I’M, RADIOACTIVE, RADIOACTIVE
He’ll yeah
For Those Who Dont Know The First Song Actually Was Radioactive-Imagine Dragons
At 7:25, you say that gamma decay is the transition of an electron in the shell to a lower energy state, but it's not. It's the transition of the core, to a lower energy state formation.
THANK YOU your videos really help me
I remember learning that types of decay occur depending on the ratio of neutrons to protons. I also remember other decay-particles like positrons, and etc. Can you guys elaborate on that real quick in part 2? Thanks.
If Thorium-234 loses a beta particle, shouldn't it become Protactinium-234? Xenon only has 54 protons.
I think it's a mestake too. besides wikipedia tells thorium dacay forms Ra or Pa (1 neutrom splitting in 1 proton + 1 electron). maybe they should have a nucrear phisic consultant beside a chemestry consultant.
You are correct. This is a mistake.
Yes, it is an error
Like if you think that a Crash Course/ Thought Cafe periodic table with the little elements doodles guys would awesome.
hmmmmm...
These videos are brilliant
Thank you for this it was very helpful
bruh we’re watching you in class as classwork
i just want to say, thank you crashcourse for being...well, crashcourse., you have no idea how much your videos help me understand chemistry better ; ^ ;
i've got finals in a few days, and with the help of your videos, i think i'm going to ace it :>
Great explanation of radiation. Thumbs up, and added to favorites.
I totally love this channel!!!!!!!
Half way through this video i hear the crash course theme playing from my kitchen. I pause and shout, "MOM ARE YOU WATCHING A CRASH COURSE VIDEO?!?" She replied with, "YEAH I'M WATCHING ONE ON THE DIGESTIVE SYSYEM." To which I replied with, "I'M WATCHING A CRASH COUSE ON NUCLEAR CHEMISTRY!"
From what I’ve learned in school. I’ve had a discord conversation that taught me more than an entire semester.
It feels somber learning about radioactivity now.....best wishes with your treatment ❤❤❤
i really like what you did at the end there with the review =]
John, you made a little mistake: Gamma-decay comes from nuclei changing states. When electron emits high energy radiations because they change states its called x-rays,
you mean Hank?
yep
You missed out the anti-neutrino in the beta minus decay equation.
Thanks man.....really helped.
If making people want to punch you is your goal, mission accomplished.
+Dan Bowser How?
the only thing ima bout to beat is my meat not this mans face
Doesn't Xenon (Xe) have proton number of 54 not 91 which is Protactinium (Pa)?
Hey anthony, if you drive a car every day, then you're risking your life. It's worth it though, just like nuclear energy. Don't you think if more people learn about nuclear science, we are more likely to make it safer?
I'd love to know how many Jr, Sr high & city college teachers/instructors have incorporated these videos into their lessons.
Not only are these fun to watch, but they're easily digestible. Those two factors combined with them simply being published on UA-cam, I would think Millennials would relate to these easier. As well as, understand them as their production is fantastic and explanations are top notch.
BEAUTIFUL OUTFIT JUST WANTED TO PUT THAT OUT THERE. SO CLASSY
There was a typo! At 5:55, it should not be Xe, it should be the element Pa.
Grammar Nazi
No
Chemistry nazi
Andrea Liu, There isn't even an Xe in there, Idk what you're talking about... Helium (He) is in there! But there's no Xenon (Xe) in there.
Wrong time. It is 6:39
I KNEW SOMETHING WAS WRONG I WAS SO CONFUSED
This is the most viewed episode since the first
Hi, I've watched it taking a break from writing my thesis on nuclear fusion. Fun :)
Awesome dude!
Since when did Thorium decay straight into Xenon via Beta radiation? Thorium decays to Protactinium this way, and Xenon's atomic number is 58. Not quite sure how this happened, but it's a brilliant video anyways.
what happened to positron decay.....
I wish you would show the actual process of how the math works with half-life. But thank you for your help. I will watch this over and over again till my exam tomorrow.
THANK YOU SO MUCH I HAVE AN EXAM ON THIS TOMORROW THX HANK
While electrons do emit photons when changing energy levels, this is simply fluorescence not gamma radiation. Gamma radiation is created when the nucleus relaxes from an excited state.
YESSSS. Glad someone else caught that.
Gamma radiation is a wave, just like light is. Photons are force carriers that act like waves and particles. So depending on the element and energy level, an electron could give off Gamma radiation. Plus, if you think photons are just visible light(fluorescence), you're an idiot. All EMR (electromagnetic radiation which is carried by photons) can be emitted from electrons falling down a level state, which includes all the types said in the video but also includes radiowaves, and X rays. Just depends on initial energy state of electron and where it rests. Please, educate yourself before making mindless comments like you did
Alex is referencing the part of the video that explains gamma decay as the release of photons from electrons as they transition to lower energy states. While electrons can release gamma photons, the problem is that electrons are not the source of gamma photons during gamma decay--Alex is correct in stating that the gamma photons originate in the NUCLEUS as it relaxes from an excited state. Plus, fluorescence does not only refer to visible light--it's just refers to things that can only emit light by absorbing light first. And the term can be applied to what happens when electrons absorb and then release photons. More specifically, it's called resonance fluorescence when referring to atomic spectra, but it's still a type of fluorescence.
Parker Stromberg I am well aware of what the electromagnetic spectrum is. Although they historically have been differentiated by wavelength, the modern convention actually is to distinguish between x-rays and gamma rays based on their source. This means there is some overlap between the energy ranges of x-rays and gamma rays.
But to be clear the video is talking about gamma decay which occurs in the nucleous, and has nothing to do with the energy levels of electrons.
+Kathryn Stone I see what you guys mean now. Sorry about that
"Now You've heard of Half Life"
a hahahaha ! Yes, i'm new!
Good video, guys. Many people have pointed out, that gamma rays originate from transitions within the nucleus. I agree with that but one should still mention that electron capture reactions, which are a variant of beta decays, lead to energetic photons being emitted by an electron. Nevertheless those photons are referred to as x-rays.
Could you please talk about ions, the periodic table and how atom s bond. It'd be very helpful
If you slow this video down he seems drunk.
lmaoo thanks for sharing that was amazingly hilarious!
Haha np man
lol
Hold on. Thorium-234 decays into Protactinium-234m and definitely not Xenon-234, for two main reasons: Xenon-234 doesn't exist in any form, and Xenon's atomic number is 54 not 91, so the only way it would do that would be through trihextuple positron decay, which is completely impossible, since anything more than double is quite implausible, and would cause a huge amount of radiation. Also you should at least say that there are more types of radiation, but that you don't have time to talk about things like neutron decay, electron and neutron capture, and hypothetical things like proton decay. I knew this, and I'm only 15 (although I am the top of my class in chemistry), however it doesn't bother me much because the other episodes have been excellent, and I understand how difficult it is to explain everything in 10 minutes.
So on subbable can you just take stuff off when they're out of stock or just say you're in the process of restocking because I want a SciShow labcoat and I hope there are more being manufactured.
That really helped me in my chemistry exam
Xenon 91?! - Do you really mean Protactinium 91?
OMFG IMAGINE DRAGONS REFERENCE THOUGH IM LAUGHING
When you discuss gamma radiation, you talk about electrons being in an excited state. I know that's how much visible and near-visible light is emitted, but for nuclear gamma radiation isn't it that the nuclear arrangement of protons and neutrons is in a higher-energy excited state?
LOVE it for so many reasons but the biggies for me were Xe and at 9:10 should have 6 neutrons (along with a full notation showing mass and charge)
Usually your videos are great Hank, but I think you've been iffy on the definition of gamma radiation. While everywhere gamma rays are just a form of EM wave with an energy higher than a certain energy and CAN be produced by electron transitions in this case the more relevant definition is (I think) that those are EM waves produced IN the nucleus given that you're talking about nuclear physics. You should perhaps also have explained beta plus and beta minus decay since they differ greatly. But otherwise, given the 10 minutes I think this is great!
Aren't most gamma rays produced by nuclear transitions rather than electron transitions? 100 keV is a lot of energy for an electron transition.
Yeah, that's an inaccuracy. Though, "photons"/"gamma rays" are often used interchangebly, i.e. even when the photons are produced in ways other that nuclear transitions.
bless your soul, hank green.
thank you! 💗