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.

Filter by
Sorted by
Tagged with
1
vote
1answer
68 views

Why does the earth have more radon in some locations?

I am not a chemist so I'm not going to give specific amounts of radon; different countries use different units. My question: why do some areas have more radon? For instance, Australia has a ...
2
votes
0answers
24 views

Electric glow discharge of last 2 noble gasses

Radon is an extremely unstable noble gas. Due to this, putting it in a gas discharge lamp for a prolonged period of time is extreme hard, as pure radon is needed to give a true color, but radon decays ...
2
votes
1answer
353 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, ...
3
votes
1answer
122 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 ...
28
votes
1answer
2k 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, ...
3
votes
1answer
75 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 ...
34
votes
6answers
60k 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 ...
3
votes
1answer
125 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 ...
7
votes
1answer
104 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{...
-2
votes
1answer
130 views

Why is helium considered as a non-metal?

How can helium be considered as a non-metal based on its chemical properties? Helium is a noble gas; it does not take part in chemical reactions under ordinary conditions. But non-metals tend to gain ...
1
vote
0answers
325 views

Do XeF2 and XeF4 react with SiO2?

A question came in my test asking which of the compounds are not stored in glass. The answers were $\ce {HF, XeF6, XeF4, XeF2}$. I know about $\ce {HF} $ and $\ce {XeF6} $ but not about the other two. ...
4
votes
1answer
9k views

Why are noble gases 'gases'?

Why do group 18 elements exist as gases, why are they not found in any other physical state ?
1
vote
1answer
2k views

Why is xenon hexafluoride not stored in glass?

Why is $\ce{XeF_6}$ not stored in glass containers? Isn't the reason glass is used for most acids is that it is non-reactive?
3
votes
2answers
126 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 ...
5
votes
1answer
996 views

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 ...
4
votes
2answers
290 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: ...
16
votes
4answers
82k views

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?
2
votes
0answers
95 views

For a given period, why is the boiling point of the halogen greater than that of the noble gas?

The boiling point of bromine, a halogen, is $\pu{58.8^\circ C}$, while the boiling point of krypton, the noble gas in the same period as bromine, is $\pu{-153.4 ^\circ C}$. I thought that the larger ...
3
votes
2answers
9k 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?
19
votes
2answers
244 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 ...
11
votes
2answers
25k views

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 ...
5
votes
2answers
1k views

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" ...
-1
votes
1answer
449 views

Why is the oxidation state of Carbon (-4)?

Based on my understanding, atoms try to achieve the electronic configuration of the nearest noble gas, by losing or gaining electrons. For example, Sodium is closest to Neon, so loses an electron so ...
18
votes
3answers
2k views

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 ...
1
vote
0answers
1k views

Ar atomic radius Vs. Mg2+, Al3+ and F-

I find it difficult to understand why the Atomic radius of $\ce{Ar}$ is lower than the ionic radius of $\ce{Mg^2+}$ and $\ce{F-}$, and higher than $\ce{Al^3+}$. According to the tables I've seen: $$\...
3
votes
1answer
5k 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,...
4
votes
3answers
430 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 ...
4
votes
1answer
94 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 ...
5
votes
1answer
74 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?
1
vote
1answer
72 views

How do molecules know how to behave when a disturbance occurs in an equilibrium?

I am well aware of Le Chatelier's principle, but what causes molecules to behave in such a way, my guess is that it all has to do with rates of reactions and frequency of collisions. When at a ...
-2
votes
1answer
574 views

How come noble gases have full outer shells? [closed]

Argon has $18$ electrons overall and $8$ in the outer shell. But the $3^{rd}$ shell is supposed to have $18$ electrons. Please use A-level terms so that I can understand.
7
votes
1answer
1k views

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?
21
votes
2answers
6k views

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 ...
8
votes
1answer
159 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 ...
0
votes
3answers
2k views

What reactions produce lots of Helium?

I'm working on a pet project and I'll need some helium. I was wondering if there were any reactions that I could perform at home to produce helium cheaper than it would be to buy helium from someone ...
-1
votes
1answer
66 views

Do argon have a high energy? [closed]

Do argon have a large energy density? And what level is it on? Is it weak or have a density like gasoline. How much energy can argon store and what noble gas have the highest energy density?
-2
votes
1answer
67 views

a structure of compound related question [duplicate]

Why the structure of XeF6 is capped octahedral but not pentagonal pyramidal although there is a possibility of being pentagonal pyramidal (with lone pair below the pyramid) ?
2
votes
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 $\ce{He2^*}$?
10
votes
1answer
973 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 ...
0
votes
1answer
339 views

Explain why the noble gas Kr does follow the general trend for covalent radii

Looking at covalent radii I know the trend states that as you move from LEFT to RIGHT the radii decreases due to increased nuclear charge. Up until you hit the noble gasses like neon. Neon does not ...
7
votes
1answer
598 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} &...
19
votes
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 ...
5
votes
1answer
136 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 ...
9
votes
1answer
18k views

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 ...
0
votes
1answer
6k views

Electronegativity of noble gases [duplicate]

SO, I stumbled upon a periodic table of electronegativity- http://www.thecatalyst.org/electabl.html Now I don't understand why the first 3 noble gases have blank spaces instead of the ...
3
votes
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 ...
10
votes
1answer
625 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 ...
20
votes
2answers
3k views

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 ...
-1
votes
1answer
157 views

Why most of the atoms with fully filled outer orbits are gaseous?

Most of the elements with fully filled outer orbits are gaseous in nature (He, Ne, Ar, Kr, Xe, Rn) with exception of Uuo (as per Wikipedia its solid). Why these fully filled outer orbit elements are ...
13
votes
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 ...