Here's why:

* Ba: This symbol represents the element Barium.

* 3: The subscript 3 indicates there are three Barium atoms in the compound.

* (PO₃): This represents the phosphite ion, which has a -3 charge.

* 2: The subscript 2 indicates there are two phosphite ions in the compound.

Therefore, combining these elements and their quantities, we get the name Tribarium Diphosphite.