The number of unpaired electrons in the valance shell of silicon is

Options

A. 2
B. 3
C. 1
D. 0

Answer

To determine the number of unpaired electrons in the valence shell of silicon, we can follow these steps:

### Step 1: Identify the Atomic Number of Silicon
Silicon (Si) has an atomic number of 14. This means it has 14 electrons.

**Hint:** The atomic number of an element tells you how many electrons are present in a neutral atom of that element.

### Step 2: Write the Electron Configuration
The electron configuration for silicon can be written as:
- 1s² 2s² 2p⁶ 3s² 3p²

**Hint:** The electron configuration shows how electrons are distributed among the various atomic orbitals.

### Step 3: Determine the Valence Shell
The valence shell for silicon is the third shell (n=3), which includes the 3s and 3p orbitals. The electrons in these orbitals are:
- 3s² (2 electrons)
- 3p² (2 electrons)

**Hint:** The valence shell consists of the outermost shell of electrons, which is important for determining chemical properties.

### Step 4: Count the Unpaired Electrons
In the 3p subshell, there are 2 electrons. According to Hund's rule, when filling orbitals of the same energy level, one electron goes into each orbital before any pairing occurs. Since there are 3 p orbitals and only 2 electrons, both will occupy separate orbitals, resulting in 2 unpaired electrons.

**Hint:** Unpaired electrons are those that are alone in an orbital and can participate in bonding.

### Conclusion
The number of unpaired electrons in the valence shell of silicon is **2**.

**Final Answer:** 2 unpaired electrons.

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