In a dry cell, what acts as a negative electrode?A. ZincB. GraphiteC. Ammonium chlorideD. Manganese dioxide

In a dry cell, the negative electrode is **A. Zinc**.

### Explanation:

1. **Understanding the Components of a Dry Cell**:
- A dry cell typically consists of a zinc can (the outer casing), a carbon rod (often made of graphite), and an electrolyte paste that may contain ammonium chloride or other chemicals.
- The zinc serves as the anode (negative electrode), while the carbon rod acts as the cathode (positive electrode).

2. **Electrode Reactions**:
- At the **anode** (negative electrode), oxidation occurs. In the case of a dry cell, zinc oxidizes to form zinc ions (Zn²⁺), releasing electrons:
\[
\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^{-}
\]
- These electrons then flow through the external circuit to the cathode, where a reduction reaction occurs.

3. **Role of the Electrolyte**:
- The electrolyte (e.g., ammonium chloride) facilitates the flow of ions between the anode and cathode but does not act as an electrode itself.
- Manganese dioxide, often present in the cathode compartment, helps in the reduction reaction at the cathode but is not an electrode.

### Conclusion:
- Thus, in a dry cell, the **zinc** acts as the negative electrode (anode). The correct answer is **A. Zinc**.