MCQ
The elements with the lowest atomic number that has a ground state electronic configuration of $(n - 1)\, d^6 ns^2$ is located in the
- Afifth period
- Bsixth period
- ✓fourth period
- Dthird period
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$2 {X}+\mathrm{B}_2 \mathrm{H}_6 \rightarrow\left\lfloor\mathrm{BH}_2(\mathbf{X})_2\right\rfloor^{+}\left\lfloor\mathrm{BH}_4\right]^{-}$ the amine(s) ${X}$ is$(are)$
$(A)$ $\mathrm{NH}_3$ $(B)$ $\mathrm{CH}_3 \mathrm{NH}_2$ $(C)$ $\left(\mathrm{CH}_3\right)_2 \mathrm{NH}$ $(D)$ $\left(\mathrm{CH}_3\right)_3 \mathrm{~N}$
$2K\,Cl{O_3}\xrightarrow{{}}2KCl + 3{O_2}$ law of mass action