Why do members of the noble gas family have low boiling points?
                Noble gases have low boiling points. This is because these gases have weak Vander Waal’s attractive forces among them which can be easily overcome. Hence, these elements have low boiling points. Boiling points of noble gases increase down the group due to increase in Vender Waal’s force with increase in size.
Why the name “inert gases” has now given up for zero groups of elements?
                In 1962, the first noble gas compound, Xe Pt F6 was prepared by Bartlett. Since then, many compounds of Xe and Kr have been prepared which are fairly stable. Thus, zero group elements are no larger chemically inert. Hence, the name, ‘inert gases’ has now been given up.
Some noble gases react with fluorine to form fluorides. Which do and which do not.
                Xenon and krypton react with fluorine to form fluorides due to (i) their low ionisation enthalpy and (ii) vacant d-orbital’s in their valence shell for the promotion of electrons.
Helium and neon do not form any compound due to
(i)                    Their high ionisation enthalpies and (ii) absence of vacant d-orbital in their valence shell.
Which reasons promoted Bartlett to prepare first noble gas compound?
                The preparation of first noble gas compound, XePtF6 was based on the chance discovery of O2PtF6. Bartlett predicted that Xenon should react with PtF6 to form an ionic compound since.
(i)                  The ionisation energy of oxygen gas (1166 kj mol-1) is comparable to that of Xenon (1170 kJ mol-1)
(ii)                The molecular diameter of oxygen and xenon are also similar (about 4 A0)
As predicted by him, Bartlett obtained an organic-yellow crystalline compound XePtF6 on just mixing Xe with PtF6 at room temperature.
Why argon is monoatomic?
                It has eight electrons (3s2 3p6) in its valence shell and has no tendency to gain, lose or share electrons with other atoms.
Give two characteristic of noble gases.
(i)                  They have high values of ionisation energy.
(ii)                Their electro affinity is zero.
 In what form the sizes of the inert gas measured?
                The atomic size of inter gas elements is measured in terms of Vander Waal’s radius. For a particular element, Vander Waals radius is generally larger than the covalent radius.


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