Silicon has a more exothermic electron affinity compared to Nitrogen. True or False?
The correct answer and explanation is:
Correct Answer: False
Nitrogen has a less exothermic electron affinity compared to silicon. In fact, nitrogen’s electron affinity is positive, which means energy must be supplied for it to gain an electron. This is unusual among elements in the periodic table, as most elements release energy when they gain an electron, making their electron affinities negative (exothermic).
Electron affinity is the amount of energy released or absorbed when an atom in the gas phase gains an electron to form a negative ion. A more negative (more exothermic) value indicates a greater tendency to accept an electron.
Nitrogen, with its electron configuration of 1s² 2s² 2p³, has a half-filled 2p subshell. This half-filled configuration is relatively stable due to symmetrical distribution and exchange energy. Adding another electron would result in electron-electron repulsion and disrupt this stability. Therefore, adding an electron to nitrogen is energetically unfavorable, making its electron affinity slightly positive or close to zero.
On the other hand, silicon, with an electron configuration of [Ne] 3s² 3p², does not have a half-filled p subshell. When it gains an electron, it becomes more stable by moving closer to a half-filled p orbital (3p³), which is a more stable configuration than 3p². As a result, silicon has a more exothermic electron affinity, meaning it releases energy upon gaining an electron.
In summary, nitrogen resists gaining an electron due to its stable half-filled p orbitals, while silicon readily gains an electron to achieve a more stable arrangement. Therefore, silicon has a more negative (exothermic) electron affinity than nitrogen, and the statement in the question is false.