Here's how to determine the chemical formula for lead(III) nitrate:

* Lead(III) ion: Lead(III) has a +3 charge (Pb³⁺).

* Nitrate ion: Nitrate has a -1 charge (NO₃⁻).

To balance the charges, you need three nitrate ions for every lead(III) ion. This gives you the formula:

Pb(NO₃)₃