in the electrochemical cell ni(s) | ni²⁺(1 m) || h⁺(1 m) | h₂(1 atm) | pt(s), which change will cause e of the cell to decrease?

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips. 

Is it  multiple choice

Abalanced force consists of two forces in opposite directions with equal magnitude. a balanced force implies a net force of zero.