MCQ
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- A

- ✓

- C

- D







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(Given : Energy of the electron in the first shell of the hydrogen atom is $-2.2 \times 10^{-18} \,J$; $h =6.63 \times 10^{-34}\, Js$ and $c =3 \times 10^{8} \,ms ^{-1}$ )
$(A)$ $\mathrm{O}$ $(B)$ $\mathrm{N}$ $(C)$ Be $(D)$ $\mathrm{F}$ $(E)$ $B$
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