Questions tagged [elements]

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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 ...
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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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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
129 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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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
47 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 ...
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1answer
36 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
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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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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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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 ...
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1answer
78 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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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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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 ...
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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 ...
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1answer
131 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
35 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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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
43 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
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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
74 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
55 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
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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 ...
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1answer
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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 ...
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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 ...
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2answers
258 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?
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4answers
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Can there be an atomic nucleus where there are more protons than neutrons?

As far as I know, number of protons is less that or equal to the number of neutrons in any atomic nucleus. But is there any possibility that there exists a nucleus where the number of protons exceeds ...
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Does emission-spectrum of molecule equal sum of emission-spectrum of its components

Imagine a number of elements with known emission-spectra, that form a primary chemical bond of either * ionic * covalent * metallic type. Does the emission-spectrum of the resulting molecule match the ...
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Why does formation of iron in stars doesnt produce any energy?

Why does the formation of iron in the stars doesnt produce any energy, i have a hunch that it might have something to do with the fact that iron has the highest binding energy per nucleon and hence (...
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1answer
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Finding stable superheavy elements

Finding new stable superheavy elements is big interests in nuclear physics. Nuclides with $Z>92$ are not found in nature, but can be made artificially. Usually these nuclides become more unstable ...
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Why are helium and lithium so different, while lithium and beryllium are similar?

How is it possible that helium, having 2 protons, and lithium, having 3 protons, are so different in terms of their physical properties? How come one is a gas at room temperature and the other is a ...
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1answer
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Why do the elements Tc and Pm have such low abundances?

What specific nuclear and electronic properties make these two elements (Tc & Pm) almost disappear from solar and galactic abundance tables?
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What units are represented by pr - micrometer?

In studying column abundances, I often encounter the units $pr-\mu m$. What does this stand for? Part per micrometer? how can this be an abundance unit? Incredibility I cannot figure out what it ...
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Isn't it entropy (disorderliness) that every atom in the universe is not of iron Fe?

The concept of mass defect and binding energy Iron has most mass defect and the greatest binding energy. It has the most stable nuclei. Nuclei with higher atomic number than iron undergo fission ...
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Facts about element 173 [closed]

I am watching a video about element 173 being the biggest and last element that can ever be assembled. The reason given as the last element that can be created is that the electrons would have to ...
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Bare Critical Masses of $^{241}$Am, $^{242m}$Am, $^{238}$Pu and $^{242}$Pu

$^{238}$Pu has 144 neutrons, and it has 2.8$\times$10$^{3}$ g$^{-1}$.s$^{-1}$ spontaneous fission neutrons and bare critical mass in 10 kg. $^{242}$Pu has 148 neutrons, and it has 1.7$\times$10$^{3}$ ...
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Was helium hydride really the first molecule?

This press release by NASA: https://www.nasa.gov/feature/the-universe-s-first-type-of-molecule-is-found-at-last/ When the universe was still very young, only a few kinds of atoms existed. ...
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2answers
158 views

Why, precisely, do three elements in a row (iron, cobalt, nickel) show ferromagnetism, but not the elements below them on the table?

The same is true for Neodymium, Promethium and Samarium, right? But like the first three, they are consecutive, not above and below each other. Somehow only elements in those two ferromagnetic 'hot-...
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Element creation in space

In my astronomy magazine I recently saw the periodic system revisited where the elememnts were color-coded according to their production site. For example, Hydrogen was created from the early Universe ...
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Why, precisely, is argon used in neutrino experiments?

Why is argon used in neutrino detectors? Other than liquid argon being denser than water or oil, what are its advantages?
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191 views

Why are man made substances in the periodic table?

Why are man made substances such as Berkelium and Lawrencium in the periodic table if they aren't natural substances? I thought the periodic table was suppose to have elements on it, which are the ...
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1answer
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How many known nuclides are there?

What is the current estimate for the number of nuclides? This is a very basic question, but I'm finding it remarkably hard to get a reliable, up-to-date answer. A few books published in the last 2-3 ...
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Elements Of the periodic table [duplicate]

Why even-numbered elements, with their even proton numbers are more abundant than odd-numbered elements ?
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Why do fusion and fission both release energy?

I only have high school physics knowledge, but here is my understanding: Fusion: 2 atoms come together to form a new atom. This process releases the energy keeping them apart, and is very energetic. ...
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1answer
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How quickly is momentum transferred through an object? [duplicate]

If there was a pole, that was a light year long, out in space. (Away from all physical interference.) If we pushed one end of it, would the other end move instantly? And does it's speed depend on ...
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Why is argon a noble gas but not, say, beryllium or palladium?

Why is argon a noble gas given that the 3d subshell is still empty? More generally, why is it that the filling of a p sub-shell makes an element noble rather than s, d, or f sub-shells, or completed n-...
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How are the relative abundances of isotopes of elements on Earth estimated?

"For example, of all the hydrogen isotopes on Earth, 99.985% occur as an isotope without a neutron and 0.015% as an isotope with 1 neutron. There is a third isotope with 2 neutrons, and is even more ...
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Are any two elements indistinguishable using a single measure? [closed]

According to infoplease.com, elements can be investigated using a range of different techniques to determine their fundamental properties. I'm assuming this list isn't exhaustive. Some properties ...
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What would the periodic table look like in 2 spatial dimensions? [closed]

I looked at this question https://worldbuilding.stackexchange.com/q/13094/, and I think it answers part of my question about how atomic physics would work, but I'm not sure. How many orbitals would ...
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Where do large deposits of heavy elements come from?

I understand that the heavier elements were produced by a series of fusion reactions in a series of stars. What I've never understood is why the atoms of these elements would ever coalesce together ...
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Can any element be a metal?

I was reading that hydrogen can become a metal in some cases, like in Jupiter, and the same for helium. Is this true for all non-metals?