The half life periods of four reactions labelled by A,B,C & D are 30sec,4.8 min,180sec and 16 min, respectively. The fastest reaction is

Options

A. A
B. B
C. C
D. D

Explanation

To determine which reaction is the fastest based on the given half-life periods, we will analyze the half-life values provided for each reaction.

### Step-by-Step Solution:

1. **List the Half-Life Periods:**
- Reaction A: 30 seconds
- Reaction B: 4.8 minutes
- Reaction C: 180 seconds
- Reaction D: 16 minutes

2. **Convert All Half-Life Periods to the Same Unit:**
- To make comparison easier, we will convert all half-lives to seconds.
- Reaction B: 4.8 minutes = 4.8 × 60 seconds = 288 seconds
- Reaction D: 16 minutes = 16 × 60 seconds = 960 seconds

3. **Compare the Half-Life Periods:**
- Now we have:
- A: 30 seconds
- B: 288 seconds
- C: 180 seconds
- D: 960 seconds
- The half-lives in seconds are: A = 30, B = 288, C = 180, D = 960.

4. **Identify the Fastest Reaction:**
- The fastest reaction corresponds to the shortest half-life.
- Comparing the values, we see that 30 seconds (A) is the shortest.

5. **Conclusion:**
- Therefore, the fastest reaction is Reaction A.

### Final Answer:
The fastest reaction is **Reaction A**.

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