Question

Which of the following is the correct formula of aluminium oxide?

• A. $A{l}_{2}O$
• B. $Al{}_{3}O{}_2$
• C. $Al{O}_2$
• D. $A{l}_2{O}_3$

Answer 1

The correct option is D

$A{l}_2{O}_3$

Write the valency of the symbol.

$A{l}^{+3}$ $O^{-2}$

Interchanging the valency

$2A{l}^{+3}$ $3O^{-2}$

Write interchanged number at the base

$Al{}_2$ $O_3$

Write the formula of the compound

$Al{}_{2}O{}_3$