Question

Write down the chemical formulae for Hydrogen peroxide.

Answer 1

Step 1: Identifying the symbols of the elements

Hydrogen peroxide is made up of the ions hydrogen and peroxide. Their symbols are,

hydrogen = $\mathrm{H}$ and peroxide = ${\mathrm{O}}_2$

Step 2: Identifying the valency of the elements

Valency of Hydrogen is $+1$ as it is a monovalent cation.

Valency of peroxide is $-2$ as it is a bivalent anion.

Step 3: Cross-over the valencies with symbols

Thus, the formula for Hydrogen peroxide is ${\mathrm{H}}_2{\mathrm{O}}_2$.