What is sodium amalgam and how is it obtained?

(N/A) Sodium amalgam is an alloy or mixture of sodium metal with mercury,represented as $Na-Hg$.
How to obtain sodium amalgam:
It is obtained by the electrolysis of a brine solution ($NaCl$ solution) using a mercury cathode and a carbon anode.
During the process,sodium ions $(Na^+)$ are reduced at the mercury cathode to form sodium metal,which then dissolves in the mercury to form sodium amalgam $(Na-Hg)$.