The halides of alkali metals are less ionic. Which of the following is least ionic:

Options

A. MF
B. MCL
C. MBT
D. MI

Explanation

To determine which halide of alkali metals is the least ionic, we need to analyze the ionic character of the halides based on the electronegativity of the halogens involved. Here’s a step-by-step solution:

### Step 1: Understand Ionic Character
Ionic character in a compound is influenced by the difference in electronegativity between the two elements involved. The greater the difference, the more ionic the compound is.

### Step 2: Identify the Halogens
The halogens we are considering are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

### Step 3: Determine Electronegativity Values
The electronegativity values for the halogens are as follows:
- Fluorine (F) - highest electronegativity
- Chlorine (Cl) - lower than F
- Bromine (Br) - lower than Cl
- Iodine (I) - lowest electronegativity

### Step 4: Analyze Electronegativity Trends
As we move down the group from fluorine to iodine, the electronegativity decreases. This means that the ability of the halogen to attract electrons decreases from F to I.

### Step 5: Compare Ionic Character of Alkali Metal Halides
For alkali metals (like Li, Na, K, etc.):
- Alkali metal fluoride (MF) has the highest ionic character due to the high electronegativity of fluorine.
- Alkali metal chloride (MCl) is less ionic than MF.
- Alkali metal bromide (MBr) is less ionic than MCl.
- Alkali metal iodide (MI) has the least ionic character due to the lowest electronegativity of iodine.

### Conclusion
Based on the analysis, the least ionic halide of alkali metals is the alkali metal iodide (MI).

### Final Answer
The least ionic halide of alkali metals is **alkali metal iodide (MI)**.

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