What is the net force on an electron placed at the centre of the bcc structure of CsCl?

a)

Zero

b)

c)

d)

Data is incomplete

(a)

From Coulomb’s law the force of repulsion between similar charges ( ) separated at a distance  is given by

From the symmetry of the eight charges with respect to the centre of the cube, it follows that the force at the centre due to two opposite charges cancel in pairs. Hence, the net force at centre is zero.