A certain particle carries 2.5 x 10-16 C of static electric charge. Calculate the number of electrons present in it.

Charge on one particle =1.6022×10−19C  Charge on N particles =1.6022×10−19×N C   Total charge =2.5×10−16C  Thus, 1.6022×10−19N=2.5×10−16N=2.5×10−161.6022×10−19=1560