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Which element has three shells with 8 electrons in its outermost shell?
AXe
BKr
CNe
DAr
Answer & Solution
Correct answer: D. Ar
1. An element with three shells has electron arrangement 2, 8, 8.
2. Total electrons = 18, so atomic number 18.
3. Element 18 is argon (Ar).
_Source: RRB Group D CEN-02/2018 PYQ, Q.43._
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