The most reactive metal according to the metal activity series is

Options

A. iron
B. potassium
C. platinium
D. copper

Explanation

To solve the question regarding the most reactive metal according to the metal activity series, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Metal Activity Series**: The metal activity series is a list that ranks metals based on their reactivity. The most reactive metals are placed at the top of the series, while the least reactive ones are at the bottom.

2. **List the Metals in Order of Reactivity**: The metals are arranged in the following order of reactivity:
- Potassium (K)
- Sodium (Na)
- Calcium (Ca)
- Magnesium (Mg)
- Aluminium (Al)
- Zinc (Zn)
- Iron (Fe)
- Tin (Sn)
- Lead (Pb)
- Hydrogen (H)
- Copper (Cu)
- Silver (Ag)
- Gold (Au)
- Platinum (Pt)

3. **Identify the Most Reactive Metal**: According to the activity series, the metal that is at the top of the list is the most reactive. In this case, it is Potassium (K).

4. **Conclusion**: Therefore, the most reactive metal according to the metal activity series is Potassium.

### Final Answer:
The most reactive metal according to the metal activity series is **Potassium (K)**.

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