The number of valence electrons in an atom with electronic configuration 2, 8, 2 is: MCQ with Answer and Explanation

The number of valence electrons in an atom with electronic configuration 2, 8, 2 is:
A. 12
B. 8
C. 2
D. 10
Answer: Option C
Solution (By JKExamLibrary)
Valence electrons are the electrons in the outermost shell. Configuration 2,8,2 means K=2, L=8, M=2. The outermost shell M has 2 electrons, so valency is 2, typical of Group 2 metals (Mg). These atoms lose 2 electrons to form M²⁺. The number of valence electrons determines the group in the periodic table. Elements with 2 valence electrons belong to Group 2 (alkaline earth metals).

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