Which group includes palladium, rhodium, iridium, and osmium?

Palladium, rhodium, iridium, and osmium are classified as platinum-group metals, which are known for their similar properties and behaviors in chemical reactions. These metals are often found together in nature and have high resistance to corrosion and excellent catalytic properties, making them valuable in various industrial applications, including catalytic converters, electronics, and jewelry.

The platinum-group metals include platinum, along with the four mentioned metals, and are typically characterized by their high melting points, rarity, and silvery-white appearance. Their economic importance further solidifies their classification as a distinct group related to precious metals, particularly in relation to their use in catalytic processes. Other group classifications, like rare earth metals, alkali metals, and base metals, do not encompass these specific elements and their unique properties.