Two elements gallium and oxygen combine to form a compound Ga20 3. Which among the following is the valency of galluim?

The valency of an element in a compound can be determined by its chemical formula and the known valency of the combining atom. In the compound Ga2O3 (gallium oxide), gallium (Ga) combines with oxygen (O). Oxygen typically has a valency of 2 because it has six electrons in its L shell and requires two more to complete its octet [1]. According to the principle of chemical formula construction, the total positive charge must balance the total negative charge. Since there are three oxygen atoms, the total negative valency is 6 (3 atoms × 2). To balance this, the two gallium atoms must provide a total positive valency of 6, meaning each gallium atom has a valency of 3 (6 ÷ 2). This is consistent with gallium's position in the periodic table and its electronic configuration (4s2 4p1), where it tends to donate three valence electrons.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > 4.1 BONDING IN CARBON – THE COVALENT BOND > p. 60