Question

What type of oxide would Eka-aluminium form?
(A) $E{{O}_{3}}$
(B) ${{E}_{3}}{{O}_{2}}$
(C) ${{E}_{2}}{{O}_{3}}$
(D) $EO$

Answer 1

Hint: Mendeleev predicted many of the elements which are present today in the periodic table. He predicted the existence along with the properties. He did the naming of unknown elements using the terms eka, dvi & tri, 1, 2 & 3 in Sanskrit.

Complete step by step solution:

Eka-Aluminium essentially means one after Aluminium, which is Gallium. Now we know the valency of Aluminium is 3, which will give us its oxidation state of +3. Since, Aluminium and Gallium belong to the same group their valency will also be the same which is 3. Hence, the same oxidation state. Every element desire to attain the noble gas configuration and it is easier for Gallium to lose 3 electrons rather than gaining 5 electrons. Now to form a neutral oxide, Gallium must form a compound.
Oxygen has 6 valence electrons, which gives it an oxidation state of -2. As it can gain two electrons to complete its noble gas configuration rather than losing 6 of its electrons.
As a result, 2 Ga will share its 6 electrons with 3 O atoms, which shares it 6 electrons and form the compound $G{{a}_{2}}{{O}_{3}}$, which is similar to ${{E}_{2}}{{O}_{3}}$.
So, the correct option is (c).

Note: Gallium in its solid form is a bluish-gray metal with orthorhombic crystalline structure and in very pure gallium has a shining silvery color but it does not exist in pure form in nature. It doesn’t react in air or water.