What is a substance used to decrease the rate of a chemical reaction

Your friend offers to show you an intrusive igneous rock. which of the following would you expect to see?

According to the diagram; a) identify the anode of the cell and write the half-reaction that occurs there b) write the overall equation for the reaction that occurs as the cell operates c) calculate the value of the standard cell potential ,e cell. d)write the shorthand notation of the cell above e)indicate the flow of the electrons on the diagram

What is the chemical formula for the compound formed between sodium and flour one