Barium is a chemical element with symbol Ba. It is found in various salts like barium nitrate, barium sulphate and barium carbonate as Ba2+ ion. In group V, barium ions are precipitated as their carbonates by adding ammonium carbonate to their solution. Barium ion reacts with potassium chromate to form yellow precipitate of barium chromate and it also imparts grassy green colour to the flame.
This video explains how to test the presence of barium ion in a given salt.