Comprehensively explain the relevance of chemistry to medical lab technology

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)

What is the polyatamic ion of borate