The term SILVERY-WHITE METALLIC ELEMENT can be represented by four different crossword solutions: POTASSIUM (9 letters), Magnesium (9 letters), LUTETIUM (8 letters), and Rhodium (7 letters). POTASSIUM is a soft, silvery-white metal that is highly reactive and is found in many minerals. Magnesium is a light, silvery-white metal that is the eighth most abundant element in the Earth's crust. LUTETIUM is a rare, silvery-white metal that is the last element in the lanthanide series. Rhodium is a rare, silvery-white metal that is highly resistant to corrosion and is used in jewelry and catalytic converters.