14. The diagram above describes the movement of molecules in a substance used to make fuel. What change did the fuel scientist observe in the substance? Before the process, the substance was a solid. After the process, it was a liquid. Before the process, the substance was a gas. After the process, it was a liquid. Before the process, the substance was a liquid. After the process, it was a solid. Before the process, the substance was a liquid. After the process, it was a gas