Iridium is a metallic element, and Platinum is a different metallic element.
Iridium
iridium is a family member of the platinum group it is also known as a transition metal.
Because platinum is non reactive metal
Iridium is a valuable metal and is rarer than gold or platinum. A search of the internet using "iridium coins" should reveal dozens of sites claiming to have the genuine article.
Platinum, iridium, or osmium, all of which are very low in reactivity.
Iridium is a nonmetal.
Depends on what metal and what acid. Most common metals can be attacked by some type of acid. Other more rare and exotic metal are more resistant. Gold Platinum are resistant to almost all acids except for a mixture of Nitric and Hydrochloric acid (aqua regia) and in the case of platinum the mixture must be hot. Tungsten and Tantalum are also in this category. The only metal that is completely resistant to all acids at any temperature is Iridium, a platinum group metal. So the answer would be Iridium.
Iridium's position on the periodic table indicates that it is a metal.
Iridium is a metal. It belongs to d-block elements.
Gold and Silver are the best known precious metals. Others are ruthenium, rhodium, palladium, osmium, iridium, and platinum. A metal is considered precious if it is rare.
Noble metals are called platinic metals (platinum, palladium, rhodium, osmium, iridium, ruthenium) and also gold and silver.
Iridium is a very hard, usually brittle, extremely corrosion-resistant silver-white metal with a face-centered cubic crystalline structure. It falls between platinum and osmium in Group 9 of the periodic table . It is not certain whether osmium or iridium is the most dense element.