Electron affinity: electron affinity may be defined as amount of energy released when an electron is added to neutral gaseous atom to form gaseous anion. X(g) + 1e^- → X(g) ^- Variation of electron affinity in group : Electron afinity is decrease from top to buttom in a group. because as atmic size increase attraction for extra electron decrease. Variation of electron affinity in periods : Electron affinity is increase from left to right in a periods. because as effective nuclear charge increase attraction for extra electron increase. # electron affinity first is always +ve. # successive electron affinity is always -ve. O + 1e^- →O^- neutral & - ve charge molecule no large amount of energy require and both when mix it defuse .so electron affinity of first is always +ve. O^- + 1e^- →O^2- -ve & -ve charge molecule greater repulsion between than so more energy require to mix together each other so E. A of successive is always -ve. Questi...
inorganic chemistry inorganic chemistry, atomic structure, periodic properties, covalent bond ,ionic bond, orbital, shape of orbital, numericals, dual nature wave nature bohr's postulates, hinesberg principal, quantum numbers, pauli exclusive principal, aufbau principal, limitation, electronic configuration of lanthanoids and transition elements, screening effect, shielding effect, slater rule and it's limitation.