Which of the following atoms has miniumum covalent radius

Options

A. B
B. C
C. N
D. Si

Answer

To determine which of the given atoms has the minimum covalent radius, we can follow these steps:

### Step 1: Understand the trend of covalent radius in the periodic table
The covalent radius of atoms changes as you move across a period and down a group in the periodic table:
- **Left to Right**: As you move from left to right across a period, the covalent radius decreases. This is because the number of protons increases, which pulls the electrons closer to the nucleus, resulting in a smaller atomic radius.
- **Top to Bottom**: As you move down a group, the covalent radius increases. This is due to the addition of electron shells, which increases the distance between the nucleus and the outermost electrons.

### Step 2: Identify the atoms in the question
The atoms given in the question are:
- Boron (B)
- Carbon (C)
- Nitrogen (N)
- Silicon (Si)

### Step 3: Analyze the position of each atom in the periodic table
- **Boron (B)**: Located in Group 13, Period 2
- **Carbon (C)**: Located in Group 14, Period 2
- **Nitrogen (N)**: Located in Group 15, Period 2
- **Silicon (Si)**: Located in Group 14, Period 3

### Step 4: Compare the covalent radii
- Since Boron, Carbon, and Nitrogen are in the same period (Period 2), we can compare their covalent radii directly:
- Boron has a larger radius than Carbon.
- Carbon has a larger radius than Nitrogen.
- Silicon is in Period 3, and its radius will be larger than that of the atoms in Period 2 due to the addition of an electron shell.

### Step 5: Conclusion
From the analysis, we can conclude that:
- Among Boron, Carbon, and Nitrogen, Nitrogen has the smallest covalent radius.
- Silicon, being in a lower period, has a larger radius than all three.

Thus, the atom with the minimum covalent radius among the given options is **Nitrogen (N)**.

### Final Answer
**Nitrogen (N)** has the minimum covalent radius.

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