How many elements amongst the following have at least 4 electrons in p-subshells?
`B, N, Al, Si, P, CI`

Answer

To determine how many elements among the given list have at least 4 electrons in their p-subshells, we need to analyze the electronic configurations of each element. Let's go through them step by step.

### Step 1: Identify the elements and their electronic configurations
1. **Boron (B)**: Atomic number 5
- Electronic configuration: \(1s^2 2s^2 2p^1\)
- P-subshell electrons: 1

2. **Nitrogen (N)**: Atomic number 7
- Electronic configuration: \(1s^2 2s^2 2p^3\)
- P-subshell electrons: 3

3. **Aluminum (Al)**: Atomic number 13
- Electronic configuration: \(1s^2 2s^2 2p^6 3s^2 3p^1\)
- P-subshell electrons: 1 (from 3p) + 6 (from 2p) = 7

4. **Silicon (Si)**: Atomic number 14
- Electronic configuration: \(1s^2 2s^2 2p^6 3s^2 3p^2\)
- P-subshell electrons: 2 (from 3p) + 6 (from 2p) = 8

5. **Phosphorus (P)**: Atomic number 15
- Electronic configuration: \(1s^2 2s^2 2p^6 3s^2 3p^3\)
- P-subshell electrons: 3 (from 3p) + 6 (from 2p) = 9

6. **Chlorine (Cl)**: Atomic number 17
- Electronic configuration: \(1s^2 2s^2 2p^6 3s^2 3p^5\)
- P-subshell electrons: 5 (from 3p) + 6 (from 2p) = 11

### Step 2: Count the elements with at least 4 electrons in p-subshells
Now we will summarize the number of p-subshell electrons for each element:
- Boron: 1 electron (not counted)
- Nitrogen: 3 electrons (not counted)
- Aluminum: 7 electrons (counted)
- Silicon: 8 electrons (counted)
- Phosphorus: 9 electrons (counted)
- Chlorine: 11 electrons (counted)

### Conclusion
The elements that have at least 4 electrons in their p-subshells are:
- Aluminum (7)
- Silicon (8)
- Phosphorus (9)
- Chlorine (11)

Thus, there are **4 elements** that have at least 4 electrons in their p-subshells.

### Final Answer
**4 elements**