Least stable hydride is

Options

A. stannane
B. silane
C. plumbane
D. germane

Explanation

To determine the least stable hydride among the hydrides of the carbon family (Group 14), we can follow these steps:

### Step 1: Identify the Hydrides
The hydrides of the carbon family (Group 14) include:
- Silane (SiH₄)
- Germane (GeH₄)
- Stannane (SnH₄)
- Plumbane (PbH₄)

### Step 2: Understand Stability in Hydrides
The stability of hydrides generally depends on the bond strength between the central atom and hydrogen. As we move down the group from silicon to lead, the size of the central atom increases due to the addition of electron shells.

### Step 3: Analyze Bond Strength
- As the atomic size increases, the distance between the central atom and hydrogen also increases.
- A greater distance results in weaker bonds due to reduced attraction between the positively charged nucleus of the central atom and the negatively charged hydrogen atom.

### Step 4: Compare the Hydrides
- **Silane (SiH₄)**: Strong bond due to smaller size of silicon.
- **Germane (GeH₄)**: Weaker bond than silane, but still relatively stable.
- **Stannane (SnH₄)**: Even weaker bond than germane.
- **Plumbane (PbH₄)**: The weakest bond due to the largest atomic size of lead.

### Step 5: Conclusion
Based on the analysis of bond strength and atomic size, **Plumbane (PbH₄)** is the least stable hydride among the hydrides of the carbon family.

### Final Answer
The least stable hydride is **Plumbane (PbH₄)**.

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