Which one of the following metals does not react with oxygen directly?

Metals exhibit varying degrees of reactivity with oxygen. Highly reactive metals like sodium and potassium react vigorously, while others like zinc (Zn) and iron (Fe) react to form oxide layers or rust when exposed to air [1]. Titanium (Ti) is also a reactive metal that readily forms a stable oxide layer. In contrast, platinum (Pt) is classified as a noble metal due to its extremely low chemical reactivity and stable electron configuration [1]. Noble metals, including gold and platinum, do not react with oxygen directly under standard conditions and are highly resistant to oxidation and corrosion [1]. While platinum can form oxides under specific extreme conditions or with the aid of support materials at high temperatures, it does not combine with diatomic oxygen directly in the manner that transition metals like iron or zinc do. Therefore, platinum is the metal among the choices that does not react with oxygen directly.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > Activity 3.9 > p. 42