How many of these elements have lower electron affinity than fluorine?
`Cl, S, O, N, P, Br, I, C`

Answer

To determine how many of the given elements have lower electron affinity than fluorine, we need to first understand the electron affinity values of each element in the list: Cl, S, O, N, P, Br, I, and C.

### Step 1: Understand Electron Affinity
Electron affinity is defined as the amount of energy released when an electron is added to a neutral atom in the gaseous state. Generally, electron affinity increases across a period (from left to right) and decreases down a group (from top to bottom) in the periodic table.

### Step 2: Identify the Electron Affinity of Fluorine
Fluorine has a very high electron affinity, approximately -328 kJ/mol. This means that when an electron is added to a fluorine atom, a significant amount of energy is released.

### Step 3: Compare Electron Affinities of Other Elements
Now we will compare the electron affinities of the other elements with that of fluorine:

- **Chlorine (Cl)**: Electron affinity is about -349 kJ/mol (higher than fluorine).
- **Bromine (Br)**: Electron affinity is about -324 kJ/mol (lower than fluorine).
- **Iodine (I)**: Electron affinity is about -295 kJ/mol (lower than fluorine).
- **Oxygen (O)**: Electron affinity is about -141 kJ/mol (lower than fluorine).
- **Sulfur (S)**: Electron affinity is about -200 kJ/mol (lower than fluorine).
- **Nitrogen (N)**: Electron affinity is about -7 kJ/mol (lower than fluorine).
- **Phosphorus (P)**: Electron affinity is about -72 kJ/mol (lower than fluorine).
- **Carbon (C)**: Electron affinity is about -120 kJ/mol (lower than fluorine).

### Step 4: Count the Elements with Lower Electron Affinity than Fluorine
From the comparisons, the elements with lower electron affinity than fluorine are:
- Bromine (Br)
- Iodine (I)
- Oxygen (O)
- Sulfur (S)
- Nitrogen (N)
- Phosphorus (P)
- Carbon (C)

This gives us a total of **7 elements** that have lower electron affinity than fluorine.

### Final Answer
**7 elements have lower electron affinity than fluorine.**

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