The line emission spectrum of each element is a means of identifying that element.
In the visible region, the number of colored lines in the emission spectrum of lithium equals the emission spectrum of hydrogen.
One of the applications of line emission spectra in ``food quality control and food adulteration'' is related to food products.
By observing the change in flame color due to dissolving a salt solution, one can identify the type of metal element present in it.
\textbf{77--} Which case is \underline{incorrect}?
\begin{enumerate}
\item The line emission spectrum of each element is a means of identifying that element.
\item In the visible region, the number of colored lines in the emission spectrum of lithium equals the emission spectrum of hydrogen.
\item One of the applications of line emission spectra in ``food quality control and food adulteration'' is related to food products.
\item By observing the change in flame color due to dissolving a salt solution, one can identify the type of metal element present in it.
\end{enumerate}