Question

22. Electron affinities generally become more favorable (more negative) as you move from left to right across a period. However, the electron affinity for N is less favorable than the electron affinity for C, as shown below. Explain . C(g)+e- C-(g) EA=-122kJ/mol N g)+e- N-(g) ) EA >0 kJ/mol

Answer 1

The electron affinity (EA) of an element is the energy change that occurs when an electron is added to a gaseous atom to give an anion. Because electrons added to energy levels move closer to the nucleus and therefore a stronger attraction between the nucleus and its electrons, electron affinity goes upward for groups and from left to right across periods of a periodic table.