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

Answer

To determine how many elements from the given list have lower electron affinity than fluorine, we need to analyze the electron affinity of each element in comparison to fluorine.

### Step-by-Step Solution:

1. **Understand Electron Affinity**:
- Electron affinity is the energy change when an electron is added to a neutral atom in the gas phase. Elements with high electron affinity tend to attract electrons more strongly.

2. **Identify the Electron Affinity of Fluorine**:
- Fluorine has a very high electron affinity, which is the highest among all elements. However, it is important to note that chlorine has a higher electron affinity than fluorine due to its larger atomic size.

3. **List the Elements and Their Electron Affinities**:
- The elements given are: Cl, S, O, N, P, Br, I, C.
- The approximate order of electron affinity for these elements is:
- Cl > Br > I > F > O > S > N > P > C

4. **Compare Each Element with Fluorine**:
- **Cl (Chlorine)**: Higher than fluorine.
- **S (Sulfur)**: Lower than fluorine.
- **O (Oxygen)**: Lower than fluorine.
- **N (Nitrogen)**: Lower than fluorine.
- **P (Phosphorus)**: Lower than fluorine.
- **Br (Bromine)**: Lower than fluorine.
- **I (Iodine)**: Lower than fluorine.
- **C (Carbon)**: Lower than fluorine.

5. **Count the Elements with Lower Electron Affinity**:
- From the analysis, the elements that have lower electron affinity than fluorine are: S, O, N, P, Br, I, C.
- This gives us a total of 7 elements.

### Final Answer:
- There are **7 elements** that have lower electron affinity than fluorine.