Answer:
formation of gas bubbles at electrodes
deposition of metals at electrodes 
changes in solution colour
electroplating
electrolysis
 
        
             
        
        
        
Answer:
A downward sloped line means the object is returning to the starting point.
 
        
             
        
        
        
Answer:
Work, in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force
Explanation:
at least part of which is applied in the direction of the displacement. ... To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd.