$XeF_2$ reacts with $SbF_5$ to form

Which elements were discovered by the scientists Ramsay and Glenn $T$. Seaborg?

The percentage of $Ar$ in dry air is approximately .......... $\%$. (in $\%$)

Which of the following statements is not correct?

Assertion $(A)$: Helium has the lowest boiling point $(4.2 \ K)$.
Reason $(R)$: The forces that exist between helium atoms are weak dispersion forces.

List the uses of Neon and argon gases.