Concept:
Proteins are organic compounds made up of amino acids. They contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. On average, proteins contain approximately \(16\%\) nitrogen by weight. This fact is widely used in biochemistry and nutrition to estimate protein content using nitrogen analysis.
Step 1: Recall the standard nitrogen content in proteins.
The average percentage of nitrogen present in proteins is:
\[
16\%
\]
Step 2: Identify the correct option.
Among the given options:
\[
16
\]
is the correct answer.
Hence, the correct option is:
\[
\boxed{(1)\ 16}
\]