Which one of the following has lowest `m.pt` ?

Options

A. B
B. TI
C. Al
D. Ga

Answer

To determine which of the following elements has the lowest melting point, we will analyze the melting points of each element in the given options: boron, thallium, aluminum, and gallium.

### Step-by-Step Solution:

1. **Identify the Elements**: The elements in question are boron (B), aluminum (Al), gallium (Ga), and thallium (Tl). All these elements belong to Group 13 of the periodic table.

2. **List the Melting Points**: We need to find the melting points of each of these elements:
- Boron (B): 1076 °C
- Aluminum (Al): 660 °C
- Gallium (Ga): 29.8 °C
- Thallium (Tl): 303 °C

3. **Compare the Melting Points**: Now, we will compare the melting points:
- Boron: 1076 °C
- Aluminum: 660 °C
- Gallium: 29.8 °C
- Thallium: 303 °C

4. **Identify the Lowest Melting Point**: From the comparison, we can see that gallium has the lowest melting point at 29.8 °C.

5. **Conclusion**: Therefore, the element with the lowest melting point among the given options is gallium (Ga).

### Final Answer:
The element with the lowest melting point is **gallium (Ga)**.

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