Which has the more negative electron affinity, Br or Br⁻?

Verified step by step guidance

1. Step 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.
2. Step 2: Consider the electron affinity of a neutral bromine atom (Br). When a neutral bromine atom gains an electron, it becomes a bromide ion (Br⁻), and this process releases energy, indicating a negative electron affinity.
3. Step 3: Analyze the electron affinity of the bromide ion (Br⁻). Adding an electron to an already negatively charged ion (Br⁻) is less favorable because of electron-electron repulsion, and it requires energy input, resulting in a positive or less negative electron affinity.
4. Step 4: Compare the two scenarios. The neutral bromine atom (Br) has a more negative electron affinity because it releases energy when gaining an electron, whereas the bromide ion (Br⁻) would require energy to gain an additional electron.
5. Step 5: Conclude that the neutral bromine atom (Br) has a more negative electron affinity compared to the bromide ion (Br⁻) due to the energy release when forming Br⁻ from Br.