Barring Helium, the melting and boiling points of every noble gas lie within a range of 10 degrees Celsius – True or false?
The correct option is A True All these noble gases are monoatomic gases at room temperature. The atomicity is explained by the stable valence electron configuration. Can you recall what the valence configuration in general is? These elements are gases at room temperature because in the liquid/solid states, very weak dispersion forces hold these atoms together. So to reach such states, large negative Celsius temperatures are required. Let us look at the values: NoblegasMeltingpoint(∘C)Boilingpoint(∘)CNumberofelectronsHe−−2692Ne−249−24510Ar−189−18618Kr−157−15236Xe−112−10954Rn−71−6286 As you can see, the largest range between melting point and boiling point is for Rn and this is <10 degrees Celsius. Hence the statement in the question is true!