Which of the following is a correct statement?

Options

A. Boron is diagonally related to silicon
B. Elements of third period are known as bridge elements
C. There are sixteen groups and seven periods in extended form of period table
D. Fluorine has higher electron affinity than Chlorine

Answer

To solve the question regarding which of the following statements is correct, we will analyze each statement one by one based on our knowledge of periodic properties.

### Step-by-Step Solution:

1. **Understanding Diagonal Relationship**:
- Diagonal relationships occur between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table. This phenomenon arises due to similarities in properties such as atomic size, electronegativity, and ionization energy.

**Hint**: Recall that diagonal relationships often involve elements from different groups but similar properties.

2. **Evaluating Statement 1**:
- The statement claims that boron is diagonally related to silicon. This is correct because boron (Group 13) and silicon (Group 14) exhibit similar properties, such as forming covalent compounds and being semiconductors.

**Hint**: Check for similarities in chemical behavior and properties between boron and silicon.

3. **Evaluating Statement 2**:
- This statement suggests that elements of the third period are known as bridge elements. However, this is not a standard term used in chemistry. The elements of the third period do not have a specific designation as "bridge elements" in relation to the second period.

**Hint**: Consider the definitions of terms used in chemistry and whether they are widely accepted.

4. **Evaluating Statement 3**:
- The statement mentions that there are 16 groups and 7 periods in the extended form of the periodic table. This is incorrect; the extended periodic table actually contains 18 groups and 7 periods.

**Hint**: Recall the structure of the periodic table and the number of groups it contains.

5. **Evaluating Statement 4**:
- This statement claims that chlorine has a higher electron affinity than chlorine. This is a typographical error, as it likely meant to compare chlorine with fluorine. Chlorine indeed has a higher electron affinity than fluorine due to its larger atomic size, which allows it to accommodate additional electrons more easily.

**Hint**: Compare the electron affinities of elements in the same group to understand trends.

6. **Conclusion**:
- After evaluating all statements, we find that Statement 1 is correct. Therefore, the correct answer to the question is that boron is diagonally related to silicon.

### Final Answer:
**Option 1 is the correct statement.**