Moderate

In which of the following compounds, the underlined element does not' have eight electrons in the outer shell.

Correct answer: A. BF3

  • A. BF3
  • B. H2O2
  • C. PCl3
  • D. PCl5

Explanation

The correct answer is BF3. In BF3, boron has only six electrons in its outer shell, resulting in an incomplete octet. Boron is one of the few elements that can be stable with less than eight electrons in its valence shell.In contrast, H2O2 and PCl3 both have elements that complete the octet rule with eight electrons in their outer shells. PCl5 has phosphorus with an expanded octet, containing ten electrons, not an incomplete octet.

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