Identifying Silver, Rhodium, and Platinum

How would you identify the metals (silver, rhodium, and platinum) in these bottles with metallic powder?

You have a summer internship working in a jewelry laboratory where your job is to explore the properties of some alloys (mixtures of metals) of silver, rhodium, and platinum in order to make brighter jewels at a lower cost. One day, while preparing an alloy, you accidentally left the bottles near the melting furnace, and the labels became charred (burned) and unreadable. You now have three unlabeled bottles of metallic powder. Your task is to perform experiments to identify the metals in these bottles before your supervisor returns. Practice computing the densities of unknown objects. Practice recording data and taking notes from experimental procedures. Analyze data to make valid scientific conclusions.