!!! which element has three occupied quantum shells with 4 electrons in the outermost shell

Argon. If you look at the periodic table, the noble gases (column on the furthest right of the table - labeled column 18) have fully filled electron shells. This is why noble gases (helium, neon, argon, krypton, xenon, and radon) are not very reactive with other elements - they are happy with their fully filled electron shells. So, the third element down on the noble gas column (Argon) has 3 fully filled electron shells. Periodic table courtesy of Wikipedia

(taken from Quora)

Ammonium hydroxide solution when added to the aluminium chloride it reacts and forms two new compounds called ammonium chloride and aluminium hydroxide. Thus ammonium hydroxide and aluminium chloride exchange their ions to form new compounds.