It is absolutely possible to write a correct chemical formula for copper chloride! The problem is that copper can form more than one type of ion, leading to two possible compounds:

* Copper(I) chloride: CuCl (copper has a +1 charge)

* Copper(II) chloride: CuCl₂ (copper has a +2 charge)

So, without knowing the specific oxidation state of copper, you can't definitively say which formula is correct. To be accurate, you would need to specify the oxidation state of copper, like "copper(I) chloride" or "copper(II) chloride."