Which expression gives the mass of O2 produced when 15 g Na2O2 (molar mass 78 g) reacts with water according to the question below?

This question is about electrolysis. metal spoons can be coated with silver. this is called electroplating. suggest one reason why spoons are electroplated?

Iron (3) oxide will decompose in the presence of hydrogen gas and heater to produced iron and digydrogen monoxide white a balanced chemical equation

What is the atomic number of an atom that has 6 protons