Acertain type of ship has two tanks in its engine each tank contains a different type of fuel when the engine turns on the same amount of energy is transferred out of both heels as shown in the diagram below why did fuel 1 change phase but fuel 2 stayed the same? explain what happened to the molecules of both fuels.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.