The long-range attraction between neon atoms

In Table 9.1 we have collected the dissociation energies and bond distances in the neutral species discussed above, along with the corresponding parameters for some related cations 

Problem 9.2 Use the schematic orbital energy diagram in Fig. 9.2 to assign tbe valence shell electron configurations of the molecular ions in Table 9.1. Try to find general answers to tbe two qnestions 

7 The long-range attraction between neon atoms 

While Ne atoms repel one another at short range, there is a very weak attractive force when / 310 pm. If no such attraction existed, neon would never condense to a liquid or freeze to a solid. (Condensation of a gas to form a liquid or a solid is not an effect of gravity. Why would water condense on the ceiling if it were ) This interatomic attraction also leads to deviation from ideal gas behavior at low temperatures and high pressures. 

Information about the attraction between a pair of noble gas atoms may be derived from measurements of gas properties, from spectroscopic investigations, or from molecular beam experiments. A molecular beam consists of molecules traveling with equal velocity along parallel paths. Information about interactions between the atoms or molecules in two beams may be obtained by analyzing the scattering patterns when two beams are crossed. 

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THE LONG-RANGE ATTRACTION BETWEEN NEON ATOMS... 

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