Questions tagged [elements]

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5
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137 views

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?
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What's the densest known material that has been made in macroscopic quantities?

I'm aware that the densest stable element is osmium at 22.61 g/cm3. And that there are unstable elements such as hassium and meitnerium which are predicted to have densities of 41 g/cm³ and ...
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81 views

Why are powdered silver and powdered platinum black?

The quantum-mechanical (relativistic) explanations for the observed colours of copper, silver & gold don't appear to explain the black colours of powdered silver (& powdered platinum). Can ...
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In the αβγ cosmology paper, how do the authors assume the integral of density over time in the early universe?

In the famous Alpher-Bethe-Gamow paper, the authors say: "it is necessary to assume the integral of $\sigma_n dt$ during the building-up period is equal to $5 \times 10^4 \frac{\text{g sec}}{\text{cm}^...
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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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How do experimental physicists know the decay path of transuranium elements ahead of time?

I have been watching (and enjoying) Dr. Poliakoff's YouTube videos on the synthesis of transuranium elements like Roentgenium and Copernicium, which decay so quickly that they are identified (if I ...
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66 views

How common is compromised reference data for physical properties of materials and elements?

This question concerns Monte Carlo simulation of electron scattering in complex material structures, especially the reliability of publicly available source codes and reference data for physical ...
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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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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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26 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
59 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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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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39 views

What are all the wavelengths of the dueterium spectra?

What are all the wavelengths in the spectrum of deuterium? I've searched and came up with an abstract that only lists the visible part of deuterium's spectrum (see http://myslu.stlawu.edu/~jmil/...
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37 views

Orbitals and configurations with degenerated energy

When we have to choose, given $n$, $\ell$, where to put an electron, when there are several $m$ orbitals, with the same energy, is there a concrete quantum mechanic rule or some superselection rule to ...
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122 views

How do trace element abundances show that dark matter exists in both baryonic and non - baryonic forms?

I can't seem to find an answer to this question anywhere, any help would be greatly appreciated. Thanks in advance.
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1answer
77 views

Are differences between elements besides the number of valence electrons negligible in forming matter and giving certain properties?

We were talking about life complexity, I don't know almost anything about physics, he told me that differences between elements beside the number of valence electrons are negligible and elements with ...
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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-...
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24 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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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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1answer
34 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 ...
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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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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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2answers
15 views

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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Which experimental procedures exist for determining the elemental composition of a nanostructure?

I am doing nanostructures on semiconductors with focused-ion beam lithography, and I am interested to know if the elemental composition is changed at the surface where the sputtering occurred. ...
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1answer
60 views

Burning atomic elements

when someone says "the carbon was completely burnt up" eg. in a car's engine. what does that mean?, Where does it go? I know no new elements are formed and of course it really didn't disappeared. so ...
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72 views

Is a random particle in element A “interchangeable” with its counterpart in element B?

I understand (in the layman's sense) that properties of an individual element are mainly derived from characteristics of its outer shell electrons...e.g., why is zinc so different from copper when ...
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how large can the periodic table become?

Until recently, four new chemicals were added to the periodic table, thus completing the seventh row of the same. It is four superheavy chemical elements (113, 115, 117 and 118) have been discovered ...
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87 views

Creating elements without using the basic elements

Have there ever been created an element in the history (I'm talking about the 20 well known synthetics element) without using any other of the available elements from the nature? For example, element ...