Which of the following set has all species isoelectronic__________________?
Correct answer: C. F - Ne - Na+
- A. F - Cl - Br
- B. Li+1 - Na+1 - K+1
- C. F - Ne - Na+
- D. H+ - H- - H
Explanation
F-, Ne, and Na+ each contain 10 electrons: F- has 9 + 1 electrons, Ne has 10, and Na+ has 11 - 1 electrons. Species with the same number of electrons are isoelectronic, even though their nuclear charges differ. The likely mistake is choosing Li+, Na+, and K+ because they are all positive ions, but they contain 2, 10, and 18 electrons respectively.
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