In a Millikan experiment, a 6.89E-14 kg charged oil droplet is suspended in the electric field be

In a Millikan experiment, a 6.89E-14 kg charged oil droplet is suspended in the electric field between two horizontal charged plates as shown. The potential difference between the plates is 2.50 kV and the electric field is oriented down. If the plates are 82.0 mm apart, determine how many electrons are gained or lost by the droplet. 
   use 3 significant digits for the answer   
 

 
     upper plate =  positive or negative

 
 
    direction of electric force =  left.down.up.right

 
     E =    N/C
 
     number of electrons =         
lost or gain