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The least stable in amongst the following is :A. `C^(-)`B. `B^(-)`C. `Be^(-)`D. `Li^(-)` |
Answer» Correct Answer - C `Li(1s^(2)2s^(1))rarrLi^(-)(1s^(2)2s^(2))` `Be(1s^(2)2s^(2))rarr Be^(-) (1s^(2)2s^(2)2p^(1))` `B(1s^(2)2s^(2)1p^(1)) rarr B^(-)(1s^(2)2s^(2)2p_(x)^(1)2p_(y)^(1))` `C^(-)(1s^(2)2s^(2)2p^(2))rarr C^(-) (1s^(2)2s^(2)2p^(3))` `Be^(-)` is the least stable because in the Be atom, all the subshells are completely full. Thus, on addition of `1` electron, the stable configuration is destabilized. |
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