Question

Which of the following have a complete octet?

• A. BeCl\(_2\)
• B. BF\(_3\)
• C. SnCl\(_2\)
• D. LiCl

Hint:

Remember that elements in the second period (such as carbon, nitrogen, oxygen, and fluorine) follow the octet rule strictly, while elements like boron, beryllium, and lithium are exceptions and do not always follow the rule.

Answer 1

The Correct Option is C

To determine which molecule has a complete octet, we look at the electronic configuration and the number of bonds formed by the atoms involved. A complete octet means that the atom has 8 electrons in its valence shell. - BeCl\(_2\): Beryllium (Be) is an exception to the octet rule because it only requires 4 electrons to complete its valence shell. In BeCl\(_2\), Be forms two bonds with chlorine but does not achieve a full octet. - BF\(_3\): Boron (B) is another element that does not follow the octet rule strictly. In BF\(_3\), boron only has 6 electrons in its valence shell, so it does not have a complete octet. - SnCl\(_2\): Tin (Sn) in SnCl\(_2\) follows the octet rule because it forms two bonds with chlorine and achieves a complete octet. - LiCl: Lithium (Li) in LiCl forms one bond with chlorine but does not have a complete octet. Lithium only needs 2 electrons to complete its valence shell. Therefore, SnCl\(_2\) has a complete octet.