Questions tagged [noble-gases]

Questions about elements of group 18 (group 0 in old notation) of the periodic table and their compounds, created despite the low reactivity of these elements.

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37
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6answers
62k views

Why do we use helium in balloons?

While I was looking at the periodic table today, I realised that there were gases that were much lighter than helium such as hydrogen. If hydrogen is lighter than helium, why do we insist on using ...
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1answer
3k views

What is the molecular structure of xenon hexafluoride?

Xenon hexafluoride, $\ce{XeF6}$, can be obtained by reaction of xenon with excess fluorine gas. What is the gas-phase structure of the molecule? What experimental evidence is there to support it, ...
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Why are noble gases stable

I was recently asked the question "Why are noble gases stable? with the expectation of providing an answer beyond the general explanation of "they have full valence layers" and I couldn't think of one....
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2answers
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Why do XeO and XeF8 not exist?

Since Neil Bartlett's 1962 discovery that xenon was capable of forming chemical compounds, a large number of xenon compounds have been discovered and described. Almost all known xenon compounds ...
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2answers
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Xenon and the human body

Reading this article on Wikipedia: Xenon Medical applications I see that Xenon can be used as an anesthetic, neuroprotectant and doping agent. If it is a noble gas, and thus, chemically stable, how ...
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1answer
5k views

Why can't helium be solidified at 'ordinary' pressures?

According to the UC Davis ChemWiki Chemistry of Helium, helium has a comparatively unusual property, specifically: Helium is the only element that cannot be solidified by lowering the temperature ...
19
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2answers
248 views

What happens chemically to 5'-radiolabeled aqueous thyroxine (thyroid prohormone) when its I-131 undergoes beta+gamma decay?

Related to this question about $\ce{^{14}C}$ beta decay in $\ce{CO2}$, what happens when the $\ce{^{131}I}$ in radiolabeled thyroxine (thyroid prohormone, or "T$_4$") undergoes beta-plus-gamma decay ...
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3answers
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What happens to the argon in the Haber-Bosch process?

The Haber–Bosch process is used to synthesis ammonia from atmospheric nitrogen and hydrogen derived from a hydrocarbon such as methane. The process requires high temperatures and pressures and also ...
16
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4answers
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Why do the melting and boiling points of the noble gases increase when the atomic number increases?

What causes the melting and boiling points of noble gases to rise when the atomic number increases? What role do the valence electrons play in this?
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2answers
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Can you in reality give neon a charge of +8?

First off, I am currently confused about why neon can even be ionized at all. But since it can be ionized, this is the energy required to give a mole of neon a charge of +8: ...
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1answer
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Do noble gasses besides Helium form diatomic molecules at low temperatures?

I know that at extremely low temperatures (mK and lower), Helium can form diatomic molecules. Do the other noble gasses also form molecules at extremely low temperatures?
13
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1answer
210 views

What is the geometric configuration of the four fluorine atoms during the synthesis of xenon tetrafluoride?

Neil Bartlett (1932–2008) first synthesized $\ce{XeF4}$ (and $\ce{XeF6}$) in 1962. In the synthesis, a nickel chamber is used, and heated to 400°C, causing the formation of $\ce{NiF4}$, which ...
12
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2answers
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How do noble gases bond with themselves?

Noble gases have full electron shells, which virtually blocks any other element from bonding with it. However, I've heard about cases where they bond to each other - for example, helium can ...
12
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1answer
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Why are inert gas (especially Xenon) compounds powerful oxidizing agents?

I am curious as to why compounds with inert gases, such as $\ce{XeF4}$, $\ce{XeF2}$, and $\ce{XeO3}$ are considered powerful oxidizing agents. I would attribute the phenomenon to the highly oxidized ...
10
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1answer
647 views

Stable natural helium hydride?

Reading the transcript of the Royal Society of Chemistry podcast Helium Hydride, they state that helium hydride is possibly the most ancient compound to form in the Universe. They make the assertion ...
10
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1answer
675 views

High Viscosity of Noble Gases

Why are the viscosities of noble gases higher than almost all other gases? This seems counter-intuitive since they have much weaker inter-molecular interactions and lower boiling points. Gas ...
10
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1answer
1k views

Trend in atomic radius for noble gases

In an exam, we were given the following graph and asked to explain why the slope of the change in r vs. Z changes dramatically at a point along the curve. I understand that the d block causes the ...
9
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1answer
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Electronegativity in krypton and xenon?

Why do krypton and xenon have high electronegativity? Noble gases are supposed to be "happy" with the amount of electrons they have, because they have 8 valence electrons (thus, most noble gases have ...
9
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1answer
3k views

Options for long term storage of helium?

Specifically, if I wanted to purchase a large amounts of helium, what are my options for purchasing helium in a state that is suitable for long term storage? It's my understanding that if I were to ...
8
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1answer
4k views

Why are there more fluoride compounds formed with Xenon?

Based on WebElements, of the Noble Gases, $\ce{He}$ and $\ce{Ne}$ do not react with any of the halogens; however: $\ce{HArF}$ has been detected at low temperatures (thank you to @bon and @Martin in ...
8
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1answer
110 views

Does the hydrohelium dication exist?

It is well-known that there exists the $\ce{He2^2+}$ dication, and also $\ce{HHe+}$ and $\ce{H2+}$ cations. But I could not find any definite information about the existence or inexistence of the $\ce{...
8
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1answer
163 views

How come the same reaction can be balanced in two distinct ways?

I faced this reaction which can be balanced in $2$ distinct ways which are not multiples of each other. $$\begin{align}\ce{6XeF4 + 12H2O &-> 2XeO3 + 24HF + 4Xe + 3O2}\tag{1}\\[0.4em] \ce{4XeF4 ...
7
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1answer
771 views

van der Waals coefficients for helium and neon

The values of the coefficient $b$ for helium and neon are $$\begin{array}{cc} \hline \text{Element} & b\text{ / }\mathrm{dm^3\ mol^{-1}} \\ \hline \ce{He} & 2.38 \times 10^{-2} \\ \ce{Ne} &...
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1answer
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Bonding of Lithium and Argon

I saw a meme that was joking around about Lithium and Argon bonding (see pic below). It got me wondering: Can Lithium and Argon bond in any circumstance?
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Why is zinc not considered to have a noble gas configuration?

I am wondering why we say that, for example, zinc does not have a noble gas configuration? I would like to say beforehand that this question may has its origin in a confusion about the word "shell" ...
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3answers
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Solubility of Noble Gases

I read this statement that: Xenon is the most soluble noble gas in water. My first doubt is: Why does the solubility of noble gases in water increase down the group? Even if this is the trend, ...
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0answers
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Anomaly in van der Waals constants of noble gases

In van der Waals equation for a real gas, the equation is $$\left(P + a\frac{n^2}{V^2}\right)(V - nb) = nRT$$ where $P$ is the pressure of the real gas, $n$ is the number of moles of the gas, $R$ is ...
5
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1answer
291 views

Which argon compounds exist, supported by experiment or computation?

Just as $\ce{HArF}$ was synthesized...Could something like $\ce{Li-Ar-Li}$ exist with AXE geometry $\ce{AX2E3}$? Any other argon compound proposals out there? I also know that there are some posible ...
5
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1answer
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What is the structure of the hypothetical xenon octafluoride?

According to Frlec et al.,[1] theoretical studies indicated that there is a possibility (albeit slim) that neutral xenon octafluoride ($\ce{XeF8}$) might exist. I am curious as to what structure this ...
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1answer
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Comparison of atomic radii

My teacher told me that Neon has a larger atomic radius than Fluorine.I am of the understanding that it is merely a consequence of the way we define the atomic radius and that we use Van der walls ...
5
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1answer
75 views

What makes for a good 'swimmer' in order see the filling level of Xenon gas in a vessel?

Most foams will probably get heavier due to diffusion. Is there glass balls this thin?
5
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1answer
312 views

How quickly does sulfur hexafluoride mix with the atmosphere?

A common science demonstration is to float a "boat" on sulfur hexafluoride. How long would the sulfur hexafluoride stay in the container (in the experiment linked above) if the container were to be ...
5
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1answer
140 views

Compound with a bright green emission when electrically excited

I rolled back the edit because I really am looking for the following: I am looking for an element or compound that would have a bright green emission when electrically excited and is a gas at between ...
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3answers
477 views

Is a compound composed out of gold, manganese, xenon, krypton, and oxalate possible?

Please keep in mind while reading this that I do not intend to create this, it is part of the backstory for a video game I am producing. I created a compound based on knowledge from my chemistry ...
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1answer
10k views

Why are noble gases 'gases'?

Why do group 18 elements exist as gases, why are they not found in any other physical state ?
4
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1answer
6k views

What is meant by complete outer shell? Why do the noble gases have zero valency?

Does having 8 or 2 electron in the outmost shell mean its outmost shell is full and its valency is zero? I know that the 3rd and 4th shell can contain 18 and 32 electrons. Then how can Argon's (2,8,...
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2answers
369 views

Forging steel inside a zero oxygen environment

Intro: I have watched one too many blacksmithing videos and now I have a question: is it possible to forge steel (either just reshape or "forge-weld") inside a no-oxygen environment? Scenario: ...
4
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1answer
98 views

What is the effect of Helium-based surroundings (99% Helium) on electrochemical gas sensors?

I am currently working on a project measuring gas composition of car exhaust. In order to dilute the gas concentration down to something electrochemical sensors can read, I diluted the sample with ...
3
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1answer
185 views

What is the explanation of the structure of H2XeO4?

Using the obsolete VSEPR theory I had a hard time predicting the structure of $\ce{H2XeO4}$. So I looked it up. I found the molecule via chemapps.stolaf.edu: It looks weird to me. I can't explain the ...
3
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1answer
1k views

Are ther known compounds of Argon? What is their molecular geometry and hybridisation?

Can Argon hybridize orbitals and/or form covalent-like/ionic-like compounds? Is there any study of that? I would be happy to read concrete references. What kind of molecular geometries for argon ...
3
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2answers
11k views

Structure of xenon hexafluoride

The central atom has a hybridization of $\mathrm{sp^3d^3}$. Thus, its structure should be pentagonal bipyramidal. Why is it not that but a distorted octahedron?
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1answer
87 views

Are there known compounds of caesium with oxidation number >1?

Given that the left neighbor of caesium, xenon, does have fluorides and oxides, it is not inconceivable that caesium can have oxides or fluorides with an oxidation number higher than 1. Are such ...
3
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1answer
165 views

Influence of the neighbouring molecules in a crystal at the example of XeF4

For reasons of symmetry I (without deeper chemical knowledge) supposed, that $\ce{XeF4}$ has a shape like $\ce{CH4}$. But according to Wikipedia its crystalline structure was determined by both NMR ...
3
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2answers
148 views

Acids of noble gases

Are there any other acids of noble gasses besides xenic acid? Why other ones seem to be very unstable (like perxenic), or completely unknown (acids of any other noble gases). Particularly are there ...
3
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1answer
211 views

Are there natural conditions that could enable the formation of noble gas compounds?

Noble gases were considered to be inert until compounds that include them, such as xenon trioxide (as an example) were found. My question is, what natural conditions allow the formation of noble gas ...
3
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1answer
113 views

What is the Solubility of Common Noble Gases in Concentrated Phosphoric Acid, 85% w/v?

By Henry’s Law, the concentration of a dissolving gas in a liquid is proportional to the partial pressure of that gas in contact with the liquid, mathematically, $ p = k_\mathrm{H} c$, where $p$ is ...
2
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1answer
391 views

Argon vs nitrogen for preserving wine

I have a question regarding whether argon or nitrogen is to prefer when it comes to preserving wine. Specifically, I am interested in knowing if there is a difference in preservation periods. Also, ...
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2answers
1k views

How can an excited helium dimer be formed?

Why does a collision between an excited helium molecule ($\ce{He^*}$) and a ground-state helium atom create $\ce{He2^*}$?
2
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1answer
2k views

Why are noble gases used in “neon” lamps

Neon lamps are lamps that contain noble gases... They light due to the presence of energetic levels for electrons (according to the definition of it in books). But I don't understand yet why noble ...
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1answer
2k views

London Forces and Liquifying Noble Gases

From my book, it says that 'without van der Waals (London Dispersion) forces, it would be impossible to liquefy noble gases.' Why is this the case?