Answer:
Mn, Co, H, N and O
Explanation:
When metallic Mn or Co reacts with concentrated HNO₃, they dissolve completely in the acid . The products formed are the nitrates of the metals, water and a mixture of NO and NO₂ gases. Hydrogen peroxide is added to oxidize any NO to NO₂ which is less harmful.
The equations of the reaction are given below;
Mn + HNO₃ ====> Mn(NO₃)₂ + NO + H₂O
Co + HNO₃ ====> Co(NO₃)₂ + NO + H₂O
H₂O₂ + NO ====> H₂O + NO₂
The resulting solution will be the soluble nitrates of manganese and cobalt as well water and this solution contains the following elements; Mn, Co, N, H And O.