Reaction of alkenes with halogens is explosive in the case of

Options

A. `F_(2)`
B. `Cl_(2)`
C. `Br_(2)`
D. `I_(2)`

Answer

To solve the question regarding the explosive reaction of alkenes with halogens, we can follow these steps:

### Step 1: Identify the Halogens
The halogens mentioned in the question are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

**Hint:** Remember that halogens are found in Group 17 of the periodic table and include F, Cl, Br, and I.

### Step 2: Understand the Nature of Alkenes
Alkenes are hydrocarbons that contain at least one carbon-carbon double bond (C=C). This double bond makes alkenes reactive, especially towards electrophiles.

**Hint:** Recall that alkenes are unsaturated hydrocarbons and their double bonds are sites of high electron density.

### Step 3: Electrophilic Reaction
In the presence of halogens, alkenes undergo electrophilic addition reactions. Halogens act as electrophiles due to their ability to accept electron pairs.

**Hint:** An electrophile is a species that is attracted to electrons and can accept an electron pair.

### Step 4: Analyze the Reactivity of Halogens
Among the halogens, fluorine is the most reactive due to its small size and high electronegativity. This results in a very strong bond formation with alkenes, leading to a rapid and explosive reaction.

**Hint:** Consider the bond strength and size of the halogen atoms when predicting their reactivity.

### Step 5: Conclusion
The reaction of alkenes with halogens is explosive in the case of fluorine due to its small atomic size and high reactivity. Chlorine can also react vigorously, but not as explosively as fluorine. Bromine and iodine are less reactive and do not exhibit explosive reactions with alkenes.

**Hint:** Remember that the reactivity of halogens decreases down the group in the periodic table.

### Final Answer
The reaction of alkenes with halogens is explosive in the case of **fluorine**.