Question

Which of the following is not true about helium?
(A) It has the lowest boiling point
(B) It has the highest first ionisation energy
(C) It can diffuse through rubber and plastic material
(D) It can form clathrate compounds

Answer 1

Hint: Helium abbreviated as He is a noble gas present in the periodic table. It is an odourless tasteless, inert gas present. It is having $1{s^2}$ inert gas configuration. It possesses the properties of an inert gas like less reactivity, exceptional stability and low electronegativity and is located far right in the periodic table.

Complete step by step answer:
We know that helium being a noble gas having $1{s^2}$ configuration. Here helium is having the lowest boiling point because of its small size and consequently having weak interatomic forces due to which it becomes easy to overcome these attractions. So they have the lowest boiling point. Therefore this statement is true.

For noble gases such as Helium, the first ionization enthalpy is highest because it is having a highly stable filled configuration which provides exceptional stability i.e $1{s^2}$ which is in control of the nucleus. So to remove an electron from the given subshell large energy is required. Therefore the first ionization energy of helium is highest. So it is a true statement.

Helium has an inherent property of diffusing through rubber and plastic material due to its small size. It can leak out of the materials such as containers, rubber and plastic. Therefore this statement is true.

Clathrate compounds are those caged compounds that are also non-stoichiometric compounds. These compounds are formed when atoms of the elements of a noble gas get trapped in cavities between the molecules of a compound.
e.g. xenon, krypton, xenon forms clathrates with beta quinol.
Helium does not form clathrate compounds due to its small size and they slip out of cavities formed by beta quinol molecules.
Therefore helium doesn’t form clathrate compounds. It is the right statement.

So, the correct answer is Option D.

Note: Dipole induced dipole interaction is responsible for the formation of clathrate compounds of noble gases with beta quinol. Also, the boiling point in noble gases increases with an increase in size due to an increase in the force of attraction. Helium due to its lightweight and the non-combustible property is used for the filling of balloons.