`underset("having smell")underset("White fumes")(B)overset("Moist air")larrunderset("element colourless")underset("M=Transition")(MCI_(4))overset(Zn)rarrunderset("colour")underset("Purple")(A)`
Identify the metal `M` and hence `MCl_(4)`. Explain the difference in colour of `MCl_(4)` and A.

Explanation

To solve the problem, we will follow a systematic approach to identify the metal \( M \) and the compound \( MCl_4 \), and explain the difference in color between \( MCl_4 \) and compound \( A \).

### Step 1: Identify the Metal \( M \) and \( MCl_4 \)

1. **Understanding the Clue**: The question mentions that \( MCl_4 \) produces white fumes when exposed to moist air. This indicates that the compound releases hydrochloric acid (HCl), which is known to produce white fumes.

2. **Transition Metal Chloride**: Since \( MCl_4 \) is a transition metal chloride, we need to consider transition metals that can form a \( +4 \) oxidation state and produce HCl upon hydrolysis.

...