This video lecture from Chemical Bonding (F.Sc. First Year Chemistry) covers the concept of Electron affinity and why it is shown with a negative sign, the factors which influence the electron affinity and the trend of it in the periods and groups of Periodic Table. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.