The overall charge on ClO3− is shown on the image attached to this answer. If we calculate the formal charges on each atom in the structure, we will notice that one oxygen atom has a formal charge of -1 while all other atoms have a formal charge of zero.
This gives the compound an overall charge of -1 as shown in the image attached to this answer. This is the correct Lewis structure for the compound ClO3− .
Normally, it explains that matter cannot be created or destroyed. It demonstrates different chemical reactions that help show the different transformations of the matter but will never destroy it or create it.
