Question

Which one is the least chemically reactive?

A. Ti
B. U
C. O
D. Ar
E. S

Answer 1

D. Ar

Step-by-step explanation:

Chemical reactive order: lanthanides > transition metal > O,S> Ar

Argon have noble gas element, Electron configuration: [Ne] 3s²3p⁶

so chemically inert, absence of chemical reactivity.