Which set of elements have strongest tendency to form anions ?

Options

A. Na,Cl, Al
B. Cu,Ag , Au
C. Be, F , N
D. F, Cl , Br

Explanation

To determine which set of elements has the strongest tendency to form anions, we need to analyze the given options based on the nature of the elements (metals vs. non-metals) and their ability to gain electrons.

### Step-by-Step Solution:

1. **Understanding Anions**: Anions are negatively charged ions formed when an atom gains one or more electrons. Non-metals typically have a stronger tendency to form anions because they have higher electronegativities and a greater ability to gain electrons.

2. **Identifying Non-metals**: We need to identify which elements in the provided options are non-metals, as these will have the strongest tendency to form anions.

3. **Analyzing the Options**:
- **Option 1: Sodium (Na), Chlorine (Cl), Aluminium (Al)**:
- Sodium (Na) is a metal.
- Chlorine (Cl) is a non-metal and can form an anion (Cl⁻).
- Aluminium (Al) is a metal.
- **Conclusion**: This option contains metals and only one non-metal, so it is not the strongest candidate for forming anions.

- **Option 2: Copper (Cu), Silver (Ag), Gold (Au)**:
- All three are transition metals.
- Metals tend to lose electrons to form cations, not gain electrons to form anions.
- **Conclusion**: This option is eliminated as it contains only metals.

- **Option 3: Beryllium (Be), Fluorine (F), Nitrogen (N)**:
- Beryllium (Be) is an alkaline earth metal.
- Fluorine (F) is a non-metal and can form an anion (F⁻).
- Nitrogen (N) is also a non-metal and can form an anion (N³⁻).
- **Conclusion**: This option has two non-metals but also includes a metal, so it is not the best option.

- **Option 4: Fluorine (F), Chlorine (Cl), Bromine (Br)**:
- All three are non-metals.
- They can easily gain electrons to form anions:
- Fluorine (F) forms F⁻,
- Chlorine (Cl) forms Cl⁻,
- Bromine (Br) forms Br⁻.
- **Conclusion**: This option contains only non-metals, which have the strongest tendency to form anions.

4. **Final Answer**: The set of elements with the strongest tendency to form anions is **Fluorine (F), Chlorine (Cl), and Bromine (Br)**.