Question

What type of oxide would Eka– aluminium form?
(a) EO3
(b) E3 O2
(c) E2 O3
(d) EO

NCERT Class X
Science - Exemplar Problems

Chapter_Periodic Classification of Elements

Answer 1

Aluminum : Al : has the oxidation state: +3, it can form Al ³⁺  < It has valency = +3.

So it will form Al₂ O₃. 

Answer 2

E2 O3 is the type of oxide Eka – aluminium would form.

Option (b).

Explanation:

• Eka Aluminium comes after Aluminium and it is called Gallium.
• Aluminium, which has an oxidation state of +3 will form $Al_3^+$ which has a valency of +3.
• Gallium and aluminium belong to the identical group and hence their valency is also going to the same which is 3.
• By losing 3 electrons it can attain the noble gas configuration which is the nearest.
• Now to be forming a neutral oxide, eka - aluminium is required to form a compound which is E2 O3.