Mass spectrometry | Atomic structure and properties | AP Chemistry | Khan Academy
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- Опубликовано: 7 авг 2024
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In the analytical technique of mass spectrometry, atoms or molecules are ionized using a high-energy electron beam and then separated based on their mass-to-charge ratios (m/z). The results are presented as a mass spectrum, which shows the relative abundances of the ions on the y-axis and their m/z ratios on the x-axis. This data can be used to calculate the exact masses of the atoms or molecules in the sample. View more lessons or practice this subject at www.khanacademy.org/science/a...
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Wonderful explanation (as always) Sal! Thank you for making this video. The picture is also very helpful in visualizing.
really helpful! I have been confused about this for weeks, finally I can understand it
We're going to learn this in school tomorrow! I'll be prepared then!
i actually cannot explain how much this helped me thank you so much !!
u guys explained so well, that even i that speak a different langague could understand the concepts perfectly. good job
Best explanation on the internet period
Idk, how do people come with these ideas....? it's just so...mind blowing..
Very helpful, thanks so much!
THANK YOU I LOVED THE SIMPLE EXPLANATION
thanks a lot, it was so helpful
Great and clear, thanks 😊
Thanks for the explanation!
Thank you for the helpful insight
Perfect explanation
Wonderful explanation 👏
Thanks in advanced for sharing such valuable contents. Really informative. 💐🙏🏻
Great presentation!
More useful for me... thankyou...
Wow! It’s really helpful
Very Very Nicely Explained! I watched so many other videos and they made it soo confusing! This is the best!
Which model to get for the home lab? Would love to see some “hands on” videos!
Thank you so much you really helped me🥰
You are very talented
Very good video, thanks a lot 👍.
Why isn't this version on the MCAT module?
this is ingenious!
very useful
Thankyou so much 😇🙏
You guys are the best ❤️🔥
You are welcome!
Thanks 😊
So useful! Thanks!
Thanks for this video. Great explanation!
Thank You Very Much 😁💙
Boht ala👌jeetay rhiye
simple easy to understand
TY.
Really interesting stuff
thank you
Helpful thx❤
concise, simple and very informative!
Hi! Nice graphic and video but there was something my grade 10 class noticed as I was explaining the whole "lighter ions are deflected more" thing. It would appear from the pattern of isotopes that the heaviest is being deflected the most. Am I missing something? I know you only borrowed the graphic, but as you are using it....
Thank u
Great explanation on Mass spectrometry,
always enjoy your video, very helpful.
Thank you🤙
short and simple
Why can’t uni professors just generalize a concept first and then go in depth. Why do they have to build from ground up
Exactly!
Because you might get it wrong as a base and you yourself even won't where to fix your misunderstanding as you go further. Simplifying means making it abstract thus people would mess it up
How do you know the masses of the isotopes of being deflected at the specific positions in the detector for you to know what is on the x axis of the graph
thanks a lot
i get depressed only by (imagening) what of there was no khan academy, thanks for your existence
My God this is so clever. I wish my teachers would explained it that clearly
Understood
Great
Thank you very much,I couldn’t understand but now it’s clear
After the deflection of various isotopes of the atom are recorded, how do you know what the mass of each is? How did you know, from the example in the video, that it was Zr-90 and not Zr-96 that was the most prevalent? How was mass 90 assigned to the most prevalent isotope? Because at the atomic level would it not be difficult to measure the mass of each deflected atom and from there be able to tell what the mass is and how much of it is deflected to find the most common isotope?
Mass spectrometry is a new concept for me as well but this is what I think:
The lighter the atom is the more it’s going to be deflected by the magnetic field, so the beam that’s the lowest is Zr-90 because this is the lightest atom in the sample.
@@rameenusman6118 you are correct ☺️
The mass spec is calibrated using a known standard with expected fragmentation masses. This mass spec calibration standard is most commonly PFTBA.
Do I have any control upon the distribution of the kind of ions coming out from the electrons bombardment?
In other words, do I know how many Zr+, Zr2+, Zr3+ etc. do I produce before entering the accelerating electric field?
When you take a pure sample, the amount in that sample is set by its abundance in nature. For example, if you have a pure sample of Zirconium, since the isotope Zr-90 is the most abundant naturally, 50% of the ions will always be Zr-90, its not us who can count or decide how many will be in there if the sample is pure. The objective of this experiment is to find out the abundance of each element hence in nature's control. I hope I answered what you were looking for.
This mass spectrometry was called magnet spetrum. Its iou source was 'electron ionization', though filament was heating and shooting the heat ion. The heat ion was flight between the source magnet, it called Fleming's left hand rule.
When the sample which was gaseous injected into source, the heat ion was crashed the sample ion and let them lost one electron and sample ion to be electron changed particle that would help the sample ion moved on or affected by magtific field.
Perfect
Cool
Nice
I have a question, Can it be done with plastic? What would it show? Does the concentration of uranium would lead as to the dinosaur date, or the creation of the plastic date?
Generally good, but you need to go into how the atom gets ionised in more detail.
Did AP Chem in 2016 and got 5. Good days :)
What do you mean by "deflected", exactly?
So... how can mass spec be used to analyse organic molecules? Like, how are people able to tell the protein structure by using mass spec?
What's the condition of magnetic field to separate??e istopes
Ur vedio is sooooo superb but I didn't get the point that y u have least likes
Azərbaycan dilində verdiyiniz üçün minnətdaram
Ilove you so match
Just to elucidate: an isotope is the atom which has lost some of its protons. During electron bombardment, the atom loses its electrons, not protons. How it comes reliable to use mass-spectrometry to evaluate relative abundance of isotopes in the nature?
How do we know that we knocked out only 1 and not 2 electrons? How will we know that?
Thanks😭💘💘💘💘💘💘
Spectroscopic techniques use electromagnetic radiation whereas spectrometric techniques do not involve usage of electromagnetic radiation....thus these two techniques are essentially different. The term mass spectroscopy is not used at all nowadays
This is a good video, but not the most common type of mass spectrometer. The video describes a time of flight mass spec. The most common type is a quadrupole mass spectrometer.
i love you sal
i love you
Have scientists ever even seen a proton or a neutron, or is this all based on hypotheses?
I heard this in the game half life
Vertigotrueshot ahaaha Half Life 3 is out.. kinda
short summary of the video: Different elements are made of isotopes. to identify different isotopes and their abundance in nature, chemists use Mass Spectrophotometry, a technique which not only informs them about the abundance of an isotope, but also provides crucial details such as mass number, atomic number etc.
Working:
consider a sample of Zirconium passed through the MS.
it is vaporized by the heater.
the vapor then gets ionized by an electron beam source.
the ionized vapors get accelerated between 2 electric plates.
then they acted upon by 2 strong magnetic plates.
the Isotopes with a greater mass to charge ratio face the least deflection, while, the isotopes with a low mass to charge ratio, face the highest deflection.
the detector detects this and the frequency of the ionized isotopes can be represented in the form of a graph.
the graph is plotted as follows:
along the X axis: Atomic mass (u)
along the y axis : relative abundance (%)
regarding the detection by the detector:
different isotopes are detected at different positions by the detector.
this enables the chemist to plot a chart representing the output obtained
Wait, how do they determine the degree to which the sample is charged? And I suppose a more massive isotopes would also accelerate more slowly to the point where it's path is altered? And will, therefore, likely have more time for its path to be altered by the magnets at that point, unlike the faster, lower mass isotopes, which might be more easily rerouted, but for a shorter duration. Hmmmm.... Seems like a lot of more complicated processes are occurring here than you're letting on. Not to dismiss the fine work you're doing; my mind is just rattling with questions, that's all.
how exactly are the ions accelerated -- just curious
it's physics! since ions are charged, they have chemical/electrical forces acting upon them. newton's second law says that net forces cause acceleration. so, the forces make them accelerate (i might be wrong, but i'd assume that's what it is)
anusha Yea I had that vague understanding that the charge ions were attracted/repelled and thus accelerated but I was more wondering what is causing this acceleration. A magnet? Some other kind of mechanism?
@@frankkawaitran2429 I think its just two plates with a voltage difference between them, a + plate and a - plate forms an electric field between them, a negative ion is attracted to the positively charged plate and will move towards it, you have a slit so that when the ion gets near the plate, it will go through the slit instead of getting blocked by the plate.
To move a charge you need to apply a potential difference. Depending on the polarity of the charge, the ion could move in direction of or against the generated electric field. Why? Becausr electric field exerts an electric force on a charge and the direction of this force is dependent on the polarity of the charge on that ion. In Mass Spectrometry when we bombard it with an electron beam we usually get cations ( Positively Charged) amd radicals (we will ignore radicals as we are interested in charged ions). Catians move in the direction of an electric field and when this cation passes through a magnetic field it os deflected. Why? Because magnetic force acts upon it and this magnetic force is assosciated with a moving charged particle.
Sorry, why we must choose positive ion? Why not negative ion?
Creating a positive ion by knocking out the electrons is easy than creating a negative ion by giving electrons. Mass spectrometry can work both on positive and negative ions. We can also use negative ions in a mass spectrometer to measure the masses of different isotopes. It is just common and easy to use positive ions.
I think need more proper method to teach this topic.
Please translate into urdu
Mass spectrometry and mass spectroscopy is NOT the same thing. This is really inacurate!
Un natural accent is horrible and un bearable
thank you
Great
Understood