Which statement is true about this fuel cell? It is self contained like a battery.
It continually needs to be charged.
It has an electrolyte that acts as a salt bridge.
It does not require the input of fuels from an outside source.

Two solids are mixed in a flask and stirred. after a few minutes, the flask becomes cold. which of the following best describes this reaction? a. an exothermic reaction b. a combustion reaction c. an endothermic reaction d. a decomposition reaction