Here's why:

* Chemical elements are the simplest forms of matter that cannot be broken down further by chemical means. They are represented by single symbols on the periodic table.

* CuSO₄ is a chemical compound, meaning it's formed by the chemical combination of two or more different elements.

* Cu represents the element copper.

* S represents the element sulfur.

* O represents the element oxygen.

So, CuSO₄ (copper sulfate) is a compound made from the elements copper, sulfur, and oxygen.