The central atom in does not violate the octet rule. the central atom in does not violate the octet rule. sf4 icl4- xef4 cf4 krf2
The Correct Answer and Explanation is:
The correct answer is CF₄. The central atom in CF₄ (carbon tetrafluoride) does not violate the octet rule.
Explanation:
The octet rule states that atoms tend to form bonds in such a way that each atom achieves a full valence shell of 8 electrons, resembling the electron configuration of noble gases. However, this rule is not strictly followed in all molecules, particularly in molecules with elements in the third period or beyond, where the central atom can accommodate more than 8 electrons.
Let’s evaluate each molecule in turn:
- SF₄ (Sulfur Tetrafluoride): Sulfur is the central atom in SF₄. It is in the third period and can expand its valence shell beyond 8 electrons. In SF₄, sulfur has 10 valence electrons, meaning it violates the octet rule by having more than 8 electrons in its valence shell. This happens because sulfur, being in the third period, has access to d-orbitals and can accommodate more electrons.
- ICl₄⁻ (Tetrachloroiodate ion): Iodine is the central atom in ICl₄⁻. It is a halogen in the fifth period and can also expand its valence shell. Iodine in this molecule has 12 electrons in its valence shell, which is a violation of the octet rule.
- XeF₄ (Xenon Tetrafluoride): Xenon is the central atom in XeF₄. Xenon is a noble gas and can hold more than 8 electrons in its valence shell due to the availability of d-orbitals. In XeF₄, xenon has 12 valence electrons, which violates the octet rule.
- CF₄ (Carbon Tetrafluoride): Carbon is the central atom in CF₄. Carbon is in the second period and does not have access to d-orbitals. Therefore, it follows the octet rule, with 8 electrons in its valence shell. Each fluorine atom contributes one electron, and carbon forms four single bonds with the fluorine atoms, achieving a stable octet configuration.
- KrF₂ (Krypton Difluoride): Krypton is the central atom in KrF₂. Like xenon, krypton can also expand its valence shell, which leads to more than 8 electrons in its valence shell (10 electrons in this case). Thus, it violates the octet rule.
Conclusion:
CF₄ (carbon tetrafluoride) is the only molecule in this list where the central atom follows the octet rule, with carbon having 8 electrons in its valence shell. The other molecules involve central atoms that expand their valence shells beyond 8 electrons, thereby violating the octet rule.