Question

Among the following, the molecule in which all atoms obey the octet rule is

• A. \(BCl_3\)
• B. \(BeH_2\)
• C. \(SF_6\)
• D. \(SCl_2\)

Hint:

Atoms follow the octet rule by completing 8 valence electrons, except for elements like Boron (incomplete octet) and Sulfur (expanded octet).

Answer 1

The Correct Option is D

Step 1: Understanding the Octet Rule The octet rule states that atoms tend to form compounds in which each atom has eight valence electrons, achieving a noble gas configuration. 

Step 2: Evaluating Each Molecule - \(BCl_3\) (Boron Trichloride): 
- Boron has only 6 valence electrons in this molecule. 
- It does not follow the octet rule (exception due to an incomplete octet). 
- \(BeH_2\) (Beryllium Hydride): 
- Beryllium has only 4 valence electrons. 
- It does not follow the octet rule (exception due to an incomplete octet). 
- \(SF_6\) (Sulfur Hexafluoride): 
- Sulfur has 12 valence electrons (expanded octet). 
- It does not follow the octet rule (exception due to an expanded octet). 
- \(SCl_2\) (Sulfur Dichloride): 
- Sulfur has 8 valence electrons (follows the octet rule). 
- Each chlorine atom also completes 8 valence electrons. 

Step 3: Conclusion Only \(SCl_2\) follows the octet rule completely for all atoms. Thus, the correct answer is \( \mathbf{(4)} \) \( SCl_2 \).