$\mathrm{Lassaigne}\text{'}\mathrm{s}$ test is used for the detection of which of the following elements?

$\mathrm{Lassaigne}\text{'}\mathrm{s}$ test is used to detect the presence of elements: Nitrogen (N), Sulfur (S), Chlorine (Cl), Bromine (Br) and Iodine (I). The elements present in the compound are converted from covalent form to the ionic form by fusing the compound with sodium metal. Following reactions take place

$\begin{array}{l}\mathrm{Na}+\mathrm{C}+\mathrm{N}\stackrel{\mathrm{\Delta }}{\to }\mathrm{NaCN}\\ 2\mathrm{Na}+\mathrm{S}\stackrel{\mathrm{\Delta }}{\to }{\mathrm{Na}}_2\mathrm{S}\\ \mathrm{Na}+\mathrm{X}\stackrel{\mathrm{\Delta }}{\to }\mathrm{NaX}\end{array}$