Write the formulae of the following chemical compounds:
Dinitrogen trioxide

We follow the given steps to write the formulae of any chemical compound :

1. Write the symbols for the elements present in the compound.
2. Write their respective valencies below the symbols.
3. Using the criss-cross method, assign the second valency to the first element and the first valency to the second element.
4. For complete formula, write the numerals in the subscript of the symbols of elements.

The formula of Dinitrogen trioxide will be :

Name of elements: Nitrogen Oxygen

Symbols of elements: N O

Valency of elements: 3 2

Formula: ${\mathrm{N}}_2{\mathrm{O}}_3$

Hence, the formula of Dinitrogen trioxide is ${\mathrm{N}}_2{\mathrm{O}}_3$.