Which of the following set has the strongest tendency to form anions?

Options

A. P, S, Cl
B. As, Sb, Bi
C. Fe, Co, Ni
D. Li, Be, B

Answer

To determine which set of elements has the strongest tendency to form anions, we need to analyze the electron configurations and the ability of these elements to gain electrons to achieve a stable noble gas configuration.

### Step-by-step Solution:

1. **Understanding Anion Formation**:
Anions are formed when an atom gains one or more electrons. Elements that are more electronegative and have a higher tendency to gain electrons will have a stronger tendency to form anions.

2. **Analyzing the Given Elements**:
- **Set 1**: Phosphorus (P), Sulfur (S), Chlorine (Cl)
- Phosphorus (P): Atomic number 15, electron configuration: [Ne] 3s² 3p³. It needs to gain 3 electrons to achieve the stable configuration of Argon (18 electrons).
- Sulfur (S): Atomic number 16, electron configuration: [Ne] 3s² 3p⁴. It needs to gain 2 electrons to achieve the stable configuration of Argon.
- Chlorine (Cl): Atomic number 17, electron configuration: [Ne] 3s² 3p⁵. It needs to gain 1 electron to achieve the stable configuration of Argon.

3. **Comparing the Tendency to Form Anions**:
- Chlorine has the strongest tendency to form anions because it only needs to gain 1 electron to achieve stability.
- Sulfur follows, needing 2 electrons.
- Phosphorus has the least tendency among these, needing 3 electrons.

4. **Evaluating Other Sets**:
- **Set 2**: Arsenic (As), Antimony (Sb), Bismuth (Bi)
- These elements are larger and belong to the same group as phosphorus but are heavier. Their larger atomic size makes it less favorable for them to gain electrons due to increased electron shielding and lower electronegativity.
- **Set 3**: Iron (Fe), Cobalt (Co), Nickel (Ni)
- These transition metals typically do not form anions; they tend to form cations or coordination complexes.
- **Set 4**: Lithium (Li), Beryllium (Be), Boron (B)
- These elements are more electropositive and tend to lose electrons rather than gain them, making them less likely to form anions.

5. **Conclusion**:
The set with the strongest tendency to form anions is **Phosphorus (P), Sulfur (S), and Chlorine (Cl)**. Among these, Chlorine has the highest tendency to form anions.

### Final Answer:
**The set with the strongest tendency to form anions is: Phosphorus (P), Sulfur (S), and Chlorine (Cl).**