Questions tagged [elements]

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1answer
72 views

Extrema in the Table of Nuclides [closed]

Symbolic picture of a nuclid chart: I would like to know for which $Z$ the area in the nuclide map has the greatest width and for which $N$ and the greatest height. Does anyone know? Note: I don't ...
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2answers
589 views

Why is the number of isotopes of an element bounded?

Is there a known reason why any given element has finitely many isotopes? Here I mean both stable and unstable isotopes. If we know this, do we have a reason why, for a given element, are the isotopes ...
0
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0answers
9 views

Height of capillary rise

Are there any tabular data in which you can find the values of the height of the capillary rise depending on the radius of the capillary? The type of liquid or capillary does not matter.
0
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1answer
26 views

Why does the binding energy per nucleon rise as the nucleon number rises, then go down again, with nuclei heavier than iron? [duplicate]

As the strong nuclear force is a short range force, and as it is way stronger than Coulomb force, Lumen Learning answered my question as follows: “for low-mass nuclei, the nuclear attraction dominates ...
0
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0answers
13 views

What determines if an element can melt in vacuum conditions (UHV and below)?

As part of my work, I grow thin films via thermal evaporation. However, I am still very new to it. I have noticed at under UHV conditions ($\sim~ 10^{-8}\, \rm{mbar}$) that some elements like Sulfer, ...
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2answers
64 views

Can muons be used to reach the island of stability of superheavy elements?

While reading about the island of stability of superheavy elements[0], experimental approaches and related difficulties[1], an idea has formed in my head. Since I cannot find considerations of such ...
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1answer
51 views

Can we create new elements or make old elements using nuclear fusion and fission [closed]

Is it possible to use nuclear fusion and fission to create new elements? For example, if you have a carbon dioxide molecule, break the bond between carbon and oxygen, and use nuclear fusion/fission to ...
1
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1answer
36 views

I thought specific activity was a property of the radionuclide?

How can specific activity of Mo-99 be higher for Mo-99 produced from fission than Mo-99 produced from neutron capture? I thought specific activity would be a property of Mo-99 so it will always be the ...
4
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1answer
78 views

Why is hydrogen ion much more likely to be +1 than -1?

With the chem 101 description of the periodic table, we ascribe certain "desires" to elements. Atoms "want" a full valence shell; for alkali metals, that is most easily done by ...
1
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1answer
20 views

Should all radioactive elements with HL smaller than 1000 years have 90% of their atoms already decayed on Earth?

Should all radioactive elements with HL smaller than 1000 years have 90% of their atoms already decayed on Earth? If that kind of radioactive source is found today should almost all of its atoms be ...
1
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2answers
37 views

Island of Stability in Astronomical Surveys

To the segment of nuclear physicists that predict that there is indeed an “Island of Stability” in super-heavy transuranic elements, where these atoms shouldn’t suffer the effects of radioactive ...
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0answers
23 views

Synthesis of new elements with Pb-126 as particle projectile?

Why isn’t Pb-126 used in the synthesis of new elements as a projectile against a target instead of Ca-48 considering it is heavier and has a double magic number of protons and neutrons, just like Ca-...
4
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2answers
57 views

Can you expect to see Island of Stability nuclei in matter flung off of neutron stars?

Apparently, merging neutron stars fling off baryon-rich matter that condenses into heavy elements, and this has been observed electromagnetically. It's not clear to me from the above sources whether ...
2
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1answer
75 views

Why is helium-3 stable?

Why is helium-3 stable? Besides hydrogen, helium-3 is the only isotope that has a neutron-to-proton ratio less than 1. Why is it not radioactive?
44
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3answers
4k views

At what temperature are the most elements of the periodic table liquid? [closed]

For elements where 'liquid', is relatively easy to define, at which temperature are the most elements liquid, and which ones? Assume 1 atm
1
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0answers
30 views

Why does changing the number of protons cause such a fundamental change in an element? [duplicate]

When we change the number of electrons in an atom of an element, it constitutes an ion. When we change the number of neutrons of an element it constitutes an isotope. But when we change the number of ...
3
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1answer
40 views

Why is aluminum more common in the solar system, etc. than sodium and fluorine?

I know that odd-numbered elements are less common than even-numbered ones, but why is aluminum more commonly created in the galaxy, apparently, than lighter odd-numbered elements? Sure, sodium and ...
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0answers
25 views

What are the origins of electronegativity?

Now, this might sound to be a chemistry oriented question. Today in physics class, we discussed bonds and electronegativity, and I wondered why it does originate. I would appreciate it if someone ...
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0answers
29 views

Strange behavior of Polonium — can it be accounted for by heat and/or ionizing radiation?

I have read that Polonium does things like move against air currents or migrates within containers to (I think) different parts of the container. But I also read that a .5 gram chunk will reach 500 C. ...
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1answer
69 views

Which element is A?

Which element used to be represented by the letter A? I'm guessing sulfur but this is only a guess. It's mentioned in Gamow (1930), "Mass Defect Curve and Nuclear Constitution". Proceedings ...
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1answer
49 views

What are the major difficulties to the production of elements?

Searching online about this topic only gives results about nucleosynthesis (making elements by nature) and the 24 radioactive artificial elements. Why isn't there any information about methods to make ...
0
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0answers
31 views

Are the breakdown voltages of silicon dioxide and silicone dioxide the same?

Silicon dioxide has a breakdown voltage of $> 10$ MV/cm [1]. However, I am unable to find any information about the breakdown voltage of silicone dioxide. Since silicone contains oxygen (and ...
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4answers
137 views

What is the '-235' in this question? [closed]

I am self-studying higher level physics currently, and stumbled upon this question: $1 mg$ of uranium - $235$ is completely destroyed in an atomic bomb. How much energy is liberated? I do not ...
0
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1answer
65 views

Where does americium store heat?

Molar heat capacity of the element americium is very close to $\frac{15}{2}R$, does that imply that each atom has 15 degrees of freedom? How does one account for them all?
0
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1answer
15 views

Pseudo-potential form factors for gold

Can anyone suggest a reference in which I can find the Fourier coefficients of the pseudopotential of gold? I cannot find them anywhere in literature. I need them to compute the role of plasmon decay ...
0
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1answer
128 views

Element well in periodic table

It may be a very stupid question, but still. Given a periodic table Why there is a well/hole of missing elements in atop of periodic table ? (Pictured as green area). Is this just a side-effect of ...
2
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2answers
89 views

Why does nuclear fusion not occur with nuclei with a nucleon number higher than 56? Please tell me if I am correct

Please tell me if my assumption is correct. So nuclear fusion does not occur with nuclei (with a nucleon number higher than 56) because the binding energy of the product nucleus is lower than the ...
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0answers
26 views

Why does nature have higher atomic nuclei if Iron(Fe) has higher binding energy per nucleon? [duplicate]

From the binding energy per nucleon (B.E./A) vs atomic number (Z) we know that Iron (Fe) is most stable nuclei in the nature. Here comes the question that if nature has found the stable nuclei then ...
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3answers
847 views

How does the mean momentum of a nucleon in a nucleus of mass number $A$ and atomic number $Z$ depends on $A$?

I was going through a text and it said that The mean momentum $p$ of a nucleon in a nucleus of the mass number $A$ and atomic number $Z$ depends on $A$ as $$ P\propto{A}^{-\frac{1}{3}}. $$ All that ...
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2answers
272 views

Why is there more lead and mercury in the universe than gold?

I am watching a Science Channel program on the collapse of massive stars and it got me wondering... What is the distribution of heavier than iron elements in the universe. (It is my understanding ...
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2answers
178 views

Why are atomic mass and mass number approximately the same?

I understand that mass number and atomic mass are different by definition.Mass number is the total number of nucleons and isotopic atomic mass is the average atomic weight of all the known isotopes of ...
2
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1answer
50 views

Lead to gold transmutation

While reading answers to the Were alchemist right?, I have come across the answer by @AndrewSteane. All in all he claims: But the idea that it might be possible to transform one chemical element into ...
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1answer
81 views

How can we knock out a proton specially to change one element to another?

I know one can simply excite a nucleon from a nucleus by radiating gamma rays on that nucleus, or knock the nucleus with neutrons or protons. But how can we knock out a proton specially to change one ...
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9answers
3k views

Were alchemists right? [closed]

When I was in school, I learned about alchemists, a group of scientists who sought a way to convert other materials into gold. They were never successful, so whenever I studied or read about them, ...
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0answers
14 views

What happens when chemical elements are struck by cosmic rays?

When struck by cosmic rays, chemical elements in soils and rocks emit uniquely identifiable signatures of energy in the form of gamma rays. These data can help scientists look for geologically ...
0
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1answer
92 views

Do atomic orbitals have a well-defined geometry or concrete spatial dimensions?

Can one atomic orbital be distinguished from another by its size/volume? And does this depend on the kind of atom, I mean does it differ from element to element?
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3answers
73 views

How can heavier elements be made from hydrogen atoms?

In a JRE podcast from a few years ago, talking about the idea of a universal constructor, Sam Harris said that we could go to a near-vacuum area of deep space, collect nothing but hydrogen atoms, ...
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2answers
138 views

In what sense are boron and carbon the simplest examples of degenerate atomic ground states?

According to this accepted answer, the most simple example of two atoms with degenerate ground states are boron and carbon. But hydrogen is the simplest of all which has the ground state configuration ...
0
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1answer
13 views

Mechanism of Adhesion Layers in Nanofab

When trying to deposit materials on substrates such as SiO2, one commonly uses adhesion layers such as Ti or Cr. This is mainly due to the chemical reactivity of the two elements, allowing them to ...
5
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1answer
491 views

How do I calculate the electron density of a gold atom?

I have to calculate the electron density of a gold atom. As far as I know, it is given by $\rho=e|\psi|^2$ if $\psi$ is the wave function of the electrons. The only way I know for calculate the wave ...
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1answer
45 views

Ductile metal makes sharper edge?

I've read that, because it is so malleable, gold can be made into an extremely thin sheet, thinner than most other metals. Coming straight to the point, my question would be: While it would wear out ...
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0answers
27 views

Beryllium Neutron Multiplier

We know that Beryllium is used in blankets of Fusion Systems because it is a neutron multiplier. I was wondering that if Beryllium is a neutron multiplier can it be used in the fission process(of ...
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1answer
60 views

Would both life as well as elementary particles no longer exist upon “heat death?

Would the elementary particles in the standard model still exist upon “heat death”? Would electrons stop orbiting around the nucleus? Would the periodic table of elements still be relevant assuming ...
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1answer
61 views

What is Neodymium?

What is Neodymium? I'm not quite sure why i was redirected here. I was curious about magnets. I wondered how magnetizing a drill bit worked. I originally wanted to know how long the magnetization ...
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1answer
82 views

Everything will not just turn into vapor in the ground zero of nuclear explosions but hydrogen plasma

Calcium atoms can't withstand extreme heat according to this link. http://abyss.uoregon.edu/~js/ast122/lectures/lec09.html "Why do some stars have strong lines of hydrogen, others strong lines of ...
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1answer
60 views

Can 40Ca II decay or change into something different

I just read the Wiki article on calcium isotopes and it said the stable calcium isotopes such as 40Ca have never been observed to decay. Then, despite the high temperature of stars such as Sun there ...
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1answer
46 views

Heavy elements creation [duplicate]

Would elements heavier than iron not be extremely rare if only created by supernovae? I believe all elements above hydrogen are created in the star's corona. Hydrogen fusion is not possible in star's ...
0
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1answer
35 views

Can another element “burn” at the same rate as hydrogen does in our sun?

From what I understand our sun doesn't actually "burn", instead a nuclear reaction is taking place, which is the cause of heat, light and a electromagnetic radiation. I believe this is called Hydrogen ...
0
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1answer
39 views

Color of radium's glow?

Does the radium salt (or metal for instance) glow only because the emitted alpha particles bombard the nitrogen atoms in the air? Still, how does that lead to a glow anyway? What's the color of the ...
2
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2answers
423 views

Is there a limit of electrons a single hydrogen atom can have?

Is there a limit of electrons a single hydrogen atom can have? If so what is it? why? Is the the answer to why scalable to helium?