\textbf{206-} In which reaction, the energy released is called the lattice energy of magnesium chloride?
\begin{enumerate}
\item[(1)] $\text{Mg}^{2+}(\text{s}) + 2\text{Cl}^-(\text{g}) \rightarrow \text{MgCl}_2(\text{s})$
\item[(2)] $\text{Mg}(\text{s}) + \text{Cl}_2(\text{g}) \rightarrow \text{MgCl}_2(\text{s})$
\item[(3)] $\text{Mg}^{2+}(\text{g}) + 2\text{Cl}^-(\text{g}) \rightarrow \text{MgCl}_2(\text{g})$
\item[(4)] $\text{Mg}^{2+}(\text{g}) + 2\text{Cl}^-(\text{g}) \rightarrow \text{MgCl}_2(\text{s})$
\end{enumerate}