Which of the following has highest melting point?

Options

A. NaCl
B. NaBr
C. NaF
D. NaI

Explanation

To determine which of the given halogens has the highest melting point, we can follow these steps:

### Step 1: Identify the Halogens
The options provided are chlorine (Cl), bromine (Br), fluorine (F), and iodine (I). All of these elements belong to the group of halogens in the periodic table.

### Step 2: Understand the Trend in Melting Points
In the halogen group, the melting points and boiling points generally increase as you move down the group from fluorine to iodine. This trend is due to the increase in atomic size and the corresponding increase in van der Waals forces (intermolecular attractions) as the number of electrons increases.

### Step 3: List the Melting Points of Each Halogen
- **Fluorine (F)**: Melting point is approximately -219.6 °C
- **Chlorine (Cl)**: Melting point is approximately -101.5 °C
- **Bromine (Br)**: Melting point is approximately -7.2 °C
- **Iodine (I)**: Melting point is approximately 113.7 °C

### Step 4: Compare the Melting Points
From the melting points listed:
- Fluorine has the lowest melting point.
- Chlorine has a higher melting point than fluorine.
- Bromine has a higher melting point than chlorine.
- Iodine has the highest melting point among them.

### Step 5: Conclusion
Thus, the halogen with the highest melting point is **iodine (I)**.

### Final Answer
**Iodine (I) has the highest melting point among the given options.**

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