What are the Group 6 elements called?

Do you mean $\text{Group VI}$ or $\text{Group 6}$?
$\text{Group 6}$ are the $\text{chromium metals, chromium, molybdenum,}$ $\text{tungsten.}$
I presume you mean $\text{Group VI elements}$, $\text{the chalcogens}$, $\text{oxygen, sulfur, selenium, tellurium.........}$
Both oxygen and sulfur have a tendency to oxidize other materials, themselves being reduced to ${O}^{2 -}$ and ${S}^{2 -}$.