Question

I couldn't understand the part when Prof.Lewin Tells us that +&- charges attract & the electrons end up somewhere else-polarization...If they attract why do they go away from each other???

Answer 1

Before applying the external field the centre of the nucleus and that of the electron cloud distribution are one and the same. But after applying an external field they are seperated by a distance as shown in the drawing because of the fact that the opposite charges attract each other and the like charges repel each other. Hence by applying an external field we polarized the charge distribution in a atom.