Which of the following is most reactive ?

Options

A. `H_(2)`
B. H (nascent)
C. `D_(2)`
D. H (atomic)

Answer

To determine which of the given options is the most reactive form of hydrogen, we will analyze each option step by step.

### Step 1: Identify the Options
We have four options to consider:
1. H2 (Dihydrogen)
2. D2 (Deuterium)
3. Nascent Hydrogen
4. Atomic Hydrogen

### Step 2: Analyze H2 and D2
- **H2 (Dihydrogen)** and **D2 (Deuterium)** are diatomic molecules.
- Both have a stable electron configuration similar to noble gases (like helium), which makes them relatively stable and less reactive.
- Since they are stable, they do not react quickly.

### Step 3: Analyze Nascent Hydrogen
- **Nascent Hydrogen** is produced during certain chemical reactions, such as when zinc reacts with sulfuric acid (H2SO4).
- It is in an active state and is known to be very reactive because it is not in a stable form.
- The formation of nascent hydrogen releases energy, which increases its reactivity.

### Step 4: Analyze Atomic Hydrogen
- **Atomic Hydrogen** is produced through the dissociation of diatomic hydrogen (H2) at very high temperatures (around 3700 K).
- This process requires energy input (approximately +43.9 kJ), but once formed, atomic hydrogen is highly reactive due to its unstable nature.
- However, atomic hydrogen has a very short lifetime and tends to recombine quickly to form H2.

### Step 5: Compare Reactivity
- Between H2 and D2, both are stable and less reactive.
- Nascent hydrogen is highly reactive due to its formation process and energy release.
- Atomic hydrogen is also very reactive, but its short lifetime limits its reactivity in practical scenarios.

### Conclusion
Considering the above analysis, **Nascent Hydrogen** (Option 3) is the most reactive form of hydrogen due to its active state and energy release during formation.

### Final Answer
The most reactive form of hydrogen among the options is **Option 3: Nascent Hydrogen**.

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