An oxide of copper is decomposed forming copper metal and oxygen gas. A 0.500 g sample of this oxide is decomposed, forming 0.444 g of copper metal. What is the empirical formula of the copper oxide

Explanation:

.5 g of copper oxide contains .444 g of copper .

its oxygen content = .5 - .444 = .056 g

moles of copper = .444 / 63.5 =  7 x 10⁻³ moles

moles of oxygen atom = .056 / 16 = 3.5 x 10⁻³ moles

ratio of copper and oxygen = 2 : 1

empirical formula of copper oxide = Cu₂O.

answer; i believe that the correct answer is (a) potassium(k)

what is the question here. i think you messed up.