Helium gas can be converted to the liquid form by the _______.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. London forces of attraction.
Helium is a nonpolar atom and does not exhibit dipole-dipole, dipole-induced dipole, or hydrogen bonding interactions. However, it can liquefy at extremely low temperatures due to London dispersion forces, which are the only intermolecular forces acting between noble gas atoms like helium.
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London forces (dispersion forces) arise from temporary fluctuations in the electron cloud, creating instantaneous dipoles.
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Though very weak in helium, these forces are enough to allow helium atoms to come close together and form a liquid at around 4.2 K under pressure.