There are zero Zn atoms in the compound (ClO₃)₂.

Here's why:

* (ClO₃)₂ represents the compound chlorate, where:

* Cl is chlorine

* O is oxygen

* The subscript '2' indicates two chlorate ions (ClO₃⁻)

* Zn represents the element zinc.

This compound doesn't contain any zinc. It is important to look at the chemical formula carefully to identify the elements present.