Question

Element ‘X’ forms an oxide with the formula X₂O₃ which is a solid with high melting point. ‘X’ would most likely be placed in the group of the Periodic Table as:

1. 1. Na
   2. Mg
   3. Al
   4. Si
2. Justify your answer in the above question (1).

Answer 1

1. Al
2. The element ‘X’ produces a trivalent oxide, as indicated by the formula X₂O₃. As a result, ‘X’ has a valency of 3, much as Al (the valencies of Na, Mg, and Si are 1, 2, and 4, respectively). The elements in Group 13 usually form oxides with the general formula X₂O₃, where ‘X’ stands for the element. Strong ionic connections between the metal cations and the oxide anions give the oxides of group 13 elements, including aluminium oxide (Al₂O₃), their high melting temperatures.