SEQ 4.2 The first electron affinity of oxygen is -141kJmol^-1 while the second electron affinity is +798 kJmol^-1 Explain.

The first electron affinity of oxygen refers to the energy change that occurs when one electron is added to a neutral oxygen atom to form an oxide ion (O^2-). The second electron affinity refers to the energy change that occurs when a second electron is added to the oxide ion to form a peroxide ion (O^2^2-).<br /><br />The first electron affinity of oxygen is negative because energy is released when an electron is added to a neutral oxygen atom. This is because oxygen has a high electronegativity and a strong tendency to gain electrons to achieve a stable electron configuration.<br /><br />The second electron affinity of oxygen is positive because energy is required to add a second electron to the oxide ion. This is because the oxide ion already has a negative charge, and adding a second electron increases the repulsion between the electrons. Therefore, energy is required to overcome this repulsion and add the second electron.<br /><br />In summary, the first electron affinity of oxygen is negative because energy is released when an electron is added to a neutral oxygen atom, while the second electron affinity is positive because energy is required to add a second electron to the oxide ion.