Potassium metal is heated strongly in O₂. It not produces

→Li forms only monoxides
4Li + O₂ → 2Li₂O
→Na,K forms monoxides & peroxides

K+O₂$\to$K₂ O

K+O₂ $\to$K₂O₂

 K + O₂ → KO₂ superoxide
→ K form all 3-types of oxides and does not produce KO