How Rutherford Discovered Radioactive Decay
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- เผยแพร่เมื่อ 14 ต.ค. 2024
- Ernest Rutherford was a research student under J.J. Thomson when a discovery would change his life forever: Radioactivity by Becquerel. From that point on, Rutherford would devote his life to the atom and radioactivity, and this video summarizes the first few experiments he did in this field that contributed heavily to nuclear physics and won him the Nobel Prize in Chemistry in 1908.
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Hello guys! I made a mistake in this video!
The mistake was in saying that one would expect a linear decay if only measuring alpha or beta particles passing through the metal plates, when in fact it would still be exponential!
If a sheet of metal blocks, say, 20% of all particles that reach it, then the probability that a particle would make it through 1 sheet is 80%, 2 sheets is 64%, 3 sheets is 51.2%, 4 sheets is 40.1%... this is exponential decay!
The reason Rutherford kept experimenting isn't because he expected linear decay, but rather because he noticed a much larger decrease than expected when he added the 12th sheet! This was when the cumulative thickness of the metal was enough to start blocking beta particles as well as alpha particles. Hope this clears things up!
Attenuation by scattering would be exponential, but where a charged particle can interact with the substance it is penetrating and be absorbed, the attenuation is not necessarily exponential.
nice video! I only whish it was longer !
Small nitpick: The electrometer does not measure current. It's an indication of Charge / Voltage
01:18 Well, yes, kind of. Narrative says that it measures electrical potential difference (in an electric current), which is correct up to the unnecessary tautology - my parentheses.
Great to hear so much in depth information about Sir Ernest Rutherford....
He was first to split the atom, is what I thought he was best known for but you have shown he did so much more than that.
The record for Radio wave transmission for example...
Thanks.....🙏🙏🇳🇿🇳🇿
Rutherford took that can of worms (three different types of decay radiation) and made sense of it. Quite an accomplishment!
Ernest Rutherford was born in New Zealand at Brightwater, Nelson. His birthplace still stands at Brightwater. Studied at Canterbury Colledge which became Canterbury University and now the Arts Centre in Christchurch, New Zealand.
Absolute legend ...
It's 1:25 AM , tomorrow I have a physics exam....but as soon as I saw that you posted a new video; I had to watch it....❤👍
Thanks for the support! Good luck on your exam 🤞
How’d the exam go ?
@@hynesie11 It was actually IIT JEE Advanced Physics practice test(part test) held by my coaching and I got 86/120.....(It was quite difficult)
That foil experiment was possibly the most important experiment in Chemistry or Physics as it hinted at just how the atom was constructed. If you think about it, the first couple of layers of Al, allowed at least a little of the Helium nuclei to pass, as it turned out. Helium nuclei, positively charged ions, zinging around like in a cloud chamber. Are there other ways ions can be formed? Like high voltage electricity? How high voltage do they have to be? Voltage multipliers or maybe a van de Graaf machine? Boggle. Thanks for the clip.
Absolutely, these experiments were extremely important, though not to be confused with the gold foil experiment conducted by Geiger and Mardsen under the direction of Rutherford a few years later!
And yes, there are other ways to create ions! Check out my videos on electrolysis. They involve ion formation through using electricity to break up ionic bonds!
I looked up "Thoron" and it is one of the isotopes of Radon.
...An isotope of radon. Yes. As is mentioned in the video.
Thoron is Radon 220, a progeny of thorium, hence the name. The usual radon is Radon 222, progeny of radium 226..
Visited his lab in Canterbury College in Christchurch, New Zealand a few years ago.
I was told, about 60 years ago, that the lab at McGill where Rutherford did his research has been sealed due to the residual radiation. I don't know if that is true or if the building where he worked is still standing. A family friend was a physics professor at McGill. He gave a talk describing the different kinds of subatomic particles and their properties at my high school.
What an awesome story, thanks for sharing!
Rutherford's on our $100 notes
Awesome, thank you
Rutherford, and Pickering who lead Pasadena's jet propulsion laboratory for the American development of space flight both attended the same small school in the tiny settlement of Havelock. Also Bob Hurst a bomb disposal expert, and Chemist also from the top of the south island oversaw as director at Dounreay for the atomic energy commission industrial research station the development of British fast reactor technology which if developed thoroughly would have been able to make use of plutonium safely for energy. Time and place
Very interesting.
One small note: I’m pretty sure he would have pronounced his surname the usual English way, with a soft “th” sound, as in “the”; rather than the way you pronounced it, with a hard th as in “thick”.
I find this presentation seems to have a fundamental defect, though given that the author seems to have read the original material it may be a simple misunderstanding or oversimplification: why WOULD you expect to see a linear drop off of some intensity effect with thickness? The automatically applicable attenuation law would be something like the Beer-Lambert law, which IS exponential (after all , the solution of a simple 1st order differential equation of absoprtion). This is what one notes with gammas - was it something special about the highly ionizing alpha or betas that would lead one to expect a linear law instead??
best regards,
DKB
An exponential decay does make sense for gamma rays, but alphas and betas are particles. Beer-Lambert applies to light only, correct?
Edit, I have noticed how I made a mistake here, thanks for pointing it out!
Turns out that the devil IS in the details , as my thesis supervisor would say. The question was a sincere one, and involves question being discussed to this day by rad experts: see, e.g, , Applied Radiation and Isotopes, V102. p63 ( in 2015 !!), by Svec. The issue at hand is that particles like light or gammas tend to either bounce off some molecular/nuclear target once or don't, to a good degree of approximation, in their range of applicability for beam attenuation. This leads to a simple diffl. absorption eqn which solves as an exponential. Highly ionizing (i.e., charged) radiations like electrons moving through matter are best described by the Bethe-Bloch equation, which is highly complicated in view of the thorny details of the close electrostatic interactions involved between projectile and atom. Nice to have my thoughts drawn to this, my friend, even if there is no simple answer one can offer. It was the basis of at least one exam question in my "Applied Particle Physics" course as a grad student at U of Toronto. best regards, DKB
I dont quite understand the linear decay. I get the fact that the superposition of 3 linear decays (alpha, beta, gamma), leads to an exponential decay, but I dont understand, why say beta decay in isolation would be linear. Surely when beta radiation passes through a medium its intensity decreases exponentially? Or am I just missing something?
Since beta radiation consists of electrons, you can expect roughly the same amount of electrons to be blocked by an identically thick layer of metal, leading to the amount of ionized gas from the electrons that make it through the layers decreasing by roughly the same amount for each additional layer of metal added.
When you say beta radiation intensity decreases exponentially, are you possibly thinking of beta radiation as a ray of light?
Edit: I noticed how I made a mistake here and put it in a pinned comment. Thanks!
Isn't it that gamma and maybe beta loses it's energy exponentionally when being stopped by a medium? I think that's not the case for alpha.
Electro-radium emits protons, ultrasound blasters
Ok this is weird, keep going, compounding any material inside should lead to non-linear, actually I'll be impressed if you could get it linear
there it is ,👏👏👏
Suprised the Aussies havent claimed him yet.
Yòu know like a bullet double the size wont go through a sheet of metal double the thickness
r^2 in a line 😊
1/r2d2, if u a spot on the wall, r3d3 doom 😊
I am become "Can of Worms"
🤣😂 ok you got me
R2D2