(1) When two helium atoms come close to one another, replusive forces overcome attractive forces
(2) All noble gases have 8 valence electrons
(3) Helium forms a compound with fluorine because of its closed shell configuration
(4) Helium is preferred to Hydrogen for filling gas balloons because its lighter and non-inflammable
$\begin{array}{1 1} Only\; (2)\; and\; (4) \\ Only \;(3)\; and\; (4) \\ (2),(3)\;and\;(4) \\ (1),(2),(3)\;and\;(4) \end{array}$
