The correct order of C–X bond polarity is:

Options

A. `CH_(3) Br gt CH_(3) Cl gt CH_(3) l`
B. `CH_(3)l gt CH_(3) Br gt CH_(3) `Cl
C. `CH_(3) Cl gt CH_(3) Br gt CH_(3)`I
D. `CH_(3) Cl gt CH_(3) I gt CH_(3)` Br

Answer

To determine the correct order of C–X bond polarity for haloalkanes, we need to consider the electronegativity of the halogens involved. The halogens we will focus on are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

### Step-by-Step Solution:

1. **Identify the Halogens**: The halogens we are considering are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

2. **Understand Electronegativity**: Electronegativity is the ability of an atom to attract shared electrons in a bond. The higher the electronegativity of an atom, the more it can attract electrons towards itself, leading to greater bond polarity.

3. **List the Electronegativity Values**: The electronegativity values for the halogens (on the Pauling scale) are approximately:
- Fluorine (F): 4.0
- Chlorine (Cl): 3.0
- Bromine (Br): 2.8
- Iodine (I): 2.5
- Astatine (At): 2.2

4. **Determine the Order of Electronegativity**: Based on the electronegativity values, we can arrange the halogens in order of decreasing electronegativity:
- F > Cl > Br > I > At

5. **Relate Electronegativity to Bond Polarity**: Since the bond polarity is directly related to the difference in electronegativity between carbon (C) and the halogen (X), we can conclude that:
- The C–F bond will be the most polar due to the high electronegativity of fluorine.
- The C–Cl bond will be next, followed by C–Br, C–I, and finally C–At.

6. **Write the Order of C–X Bond Polarity**: Therefore, the correct order of C–X bond polarity is:
- CH3F > CH3Cl > CH3Br > CH3I > CH3At

7. **Select the Correct Option**: Based on the analysis, the correct option that matches this order is option C.

### Final Answer:
The correct order of C–X bond polarity is:
**CH3F > CH3Cl > CH3Br > CH3I > CH3At**