Final answer:
Silver (Ag) is the best element to make a coin due to its properties.
Step-by-step explanation:
The element that would make the best coin out of phosphorus (P), silver (Ag), potassium (K), or xenon (Xe) is silver (Ag). Silver is a highly malleable and ductile metal with excellent conductivity, making it suitable for minting coins. It is also resistant to corrosion, which ensures the longevity of the coins.
Learn more about Properties of elements for making coins