Boron of highest purity (~99.9%)is obtained by

1.	Boron of highest purity (~99.9%)is obtained by
A.	Reduction of \[{{B}_{2}}{{O}_{3}}\]by mg.
B.	Electrolysis of fused tetrafluoroborates (\[KB{{F}_{4}}\]) in molten KF.
C.	Reduction of \[BC{{l}_{3}}\]with \[{{H}_{2}}\]at 1270 K.
D.	thermal decomposition of boranes at 1173 K.
Answer» D. thermal decomposition of boranes at 1173 K.

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Boron of highest purity (~99.9%)is obtained by

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