The elements in Group 18 are known as noble gases.In terms of their electron configurations, explain what the noble gases all have in common.

1. What is the common valence electron configuration for elements in Group 18 (noble gases) of the periodic table?

The elements of group 18 on the periodic table are called noble gases because they tend to be unreactive with most elements under most conditions.  This lack of reactivity results from the noble gases having a full valence shell, which makes participating in a reaction by gaining, losing, or sharing electrons energetically unfavorable.  Accordingly, noble gases have a very high ionization energy and a very low electron affinity.Under appropriate conditions, it is possible for species that have a very high electron affinity (eg, fluorine, oxygen) to overcome the high ionization energy of noble gas atoms and form a chemical bond.  In such cases, the reactivity of the noble gases tends to increase going down the periodic column due to the valence electrons occupying higher-energy orbitals farther from the nucleus.  As a result, xenon can form several compounds.Reactions between xenon and fluorine form relatively stable compounds but the specific compound produced depends on the ratio of these gases.  A mixture of Xe(g) and excess F2(g) produces XeF6(s) according to Reaction 1, but a mixture with a 1:2 ratio of Xe(g) to F2(g) results in the formation of XeF4(s) according to Reaction 2.Xe(g) + 3 F2(g) → XeF6(s)Reaction 1Xe(g) + 2 F2(g) → XeF4(s)Reaction 2Dissolving XeF6(s) or XeF4(s) in water forms a weakly acidic solution containing XeO3(aq), as indicated by Reactions 3 and 4.XeF6(s) + 3 H2O(l) → XeO3(aq) + 6 HF(aq)Reaction 36 XeF4(s) + 12 H2O(l) → 2 XeO3(aq) + 4 Xe(g) + 3 O2(g) + 24 HF(aq)Reaction 4XeO3 is stable in aqueous solution but as a dried solid, XeO3 is violently explosive and will detonate spontaneously upon heating or mechanical shock.  However, adding 15-crown-5 prior to isolation results in the formation of a complex (Reaction 5) that stabilizes XeO3 and makes the complex safe to isolate and dry.Reaction 5 Question 38Which of the following is the net reaction for the hydrolysis and complexation of a mixture of 6 moles XeF4 and 1 mole of XeF6 following Reactions 3, 4, and 5?  (Note:  Y = 15-crown-5.)A.XeF6 + 6 XeF4 + 15 H2O + 3 Y → 4 Xe + 3 O2 + 30 HF + 3 YXeO3B.XeF6 + 6 XeF4 + 15 H2O + Y → 6 Xe + 3 O2 + 30 HF + YXeO3C.6 XeF4 + 12 H2O + Y + XeO3 → 4 Xe + 3 O2 + YXeO3 + 24 HFD.XeF6 + 6 XeF4 + 15 H2O → 3 XeO3 + 4 Xe + 3 O2 + 30 HF

44. Which statement does not describe noble gases?1 pointThe more massive noble gases react with other elements.They belong to group VIIIA or 18.They contain at least one metalloid.He, Ne, Ar, Kr, Xe and Rn are included in the group.

What are the noble gases?A.Elements with two valence electronsB.Elements with seven valence electronsC.Elements with one valence electronD.Elements with two or eight valence electrons

Noble gases refer to the elements of Group 18 on the periodic table.  These gases are commonly used in "neon lighting" because electric current passed through a sealed glass tube containing a noble gas causes the emission of photons of visible light at specific wavelengths (ie, colors) unique to the gas that is used.Atoms of the noble gases are energetically very stable due to having electron configurations with a full valence shell.  This characteristic causes the noble gases to have very high ionization energies and electron affinities near zero.  As a result, the noble gases usually do not participate in reactions with other elements.  However, under special conditions it is possible to form a small number of noble gas compounds.  For example, species that have a very high electron affinity (eg, fluorine) can pull electrons from some noble gas atoms to form a chemical bond.  Reactions between F2(g) and Kr(g) or Xe(g) under reduced pressure can be achieved using an electrical discharge.Kr(g)+F2(g)−→−−−−electricaldischargeKrF2(s)Kr𝑔+F2𝑔→electricaldischargeKrF2𝑠Reaction 1Xe(g)+F2(g)−→−−−−electricaldischargeXeF2(s)Xe𝑔+F2𝑔→electricaldischargeXeF2𝑠Reaction 2A similar reaction can be achieved in a mixture of F2(g) and Rn(g) at an elevated temperature.Rn(g)+F2(g)−→−−400 °CRnF2(s)Rn𝑔+F2𝑔→400 °CRnF2𝑠Reaction 3The compounds formed from Reactions 1 and 2 are relatively stable and can be stored if shielded from water, heat, and light.  Although the RnF2(s) from Reaction 3 is chemically stable, it still degrades over time because radon is radioactive and undergoes nuclear decay to become isotopes of Po, Bi, and Pb.  In contrast, no stable fluorine compounds form when mixing F2(g) with He(g), Ne(g), or Ar(g). Question 35In the compounds formed in Reactions 1 and 3, the noble gas with the greatest electronegativity is:A.Kr, because it has a greater ratio of protons to neutrons in its nucleus.B.Kr, because it has fewer protons but its valence electrons are closer to its nucleus.C.Rn, because it has a greater total number of electrons.D.Rn, because it has a greater number of protons in its nucleus.