Determine which atom in the following set has the most exothermic electron affinity:N, O, C, B, Ne

• A. N
• B. O
• C. C
• D. B
• E. Ne

Answer: (B)

Verified step by step guidance

1. Understand the concept of electron affinity: Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gaseous state to form a negative ion. A more exothermic electron affinity means the atom releases more energy when gaining an electron.
2. Consider the periodic trend: Generally, electron affinity becomes more exothermic across a period from left to right due to increasing nuclear charge, which attracts the added electron more strongly.
3. Analyze the given elements: The elements provided are N, O, C, B, and Ne. These elements are in the second period of the periodic table.
4. Evaluate the electron configurations: Oxygen (O) has a higher nuclear charge than nitrogen (N), carbon (C), and boron (B), making it more likely to have a more exothermic electron affinity. Neon (Ne) is a noble gas with a full valence shell, so it has a very low or even positive electron affinity.
5. Conclude based on trends and configurations: Oxygen (O) is expected to have the most exothermic electron affinity among the given elements due to its position in the periodic table and its electron configuration.