Which of the following is not isoelectronic with any other?
Correct answer: C. Se4+
- A. Sr2+
- B. Kr
- C. Se4+
- D. Br-1
Explanation
Isoelectronic species have the same number of electrons. Sr2+ (36 electrons), Kr (36 electrons), and Br- (36 electrons) all have 36 electrons, making them isoelectronic. Se4+ has 34 electrons, so it is not isoelectronic with any of the other options.
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