Simplify the following text for a Grade 8 native English-speaking person.
Original: The element may also be prepared in an ultra-pure form through the reaction of potassium iodide with copper ( II ) sulfate , which gives copper ( II ) iodide initially .
Simplified: A very pure form of iodine is made by reacting copper sulfate and potassium iodide . This makes copper ( II ) iodide which is not stable .