Which of the following noble gases has the highest polarizability?

Helium was discovered by

In clathrates of $Xe$ with water,what is the type of bonding between $Xe$ and water molecules?

Select the $INCORRECT$ statement regarding the following reactions:
$XeF_6 + \text{excess } H_2O \rightarrow 'X' + HF$
$XeF_6 + 2 \text{ moles } H_2O \rightarrow 'Y' + HF$

Xenon tetrafluoride,$XeF_4$ is:

Which of the following gases exists more abundantly in nature than the others?