\textbf{209-} The intermolecular attractive force among the elements of group ............... is of type ............... periodic table and in group ............... \textbf{decreases} with increasing atomic mass of the elements, their melting and boiling points.
\begin{itemize}
\item[(1)] 1A, nonpolar dipole–dipole, $5A$ \hfill (2) 7A, dipole–dipole, $5A$
\item[(3)] 7A, van der Waals, metallic bonds, dipole–dipole \hfill (4) 7A, van der Waals, dipole–dipole, metallic bonds
\end{itemize}