I want to know the answer to the following question:
What did Klaproth probably create when he dissolved pitchblende in nitric acid?
All the background I'm provided with is that "Klaproth assumed the yellow substance was the oxide of a yet-undiscovered element and heated it with charcoal to obtain a black powder, which he thought was the newly discovered metal itself (in fact, that powder was an oxide of uranium).". Is that enough to answer the question?