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9 . Total num ber of vacant orbitals in valence shell of Br when it forms maximum covalent bon d

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Dear student,
The element Br has 4s²4p⁵ outer most electronic configuration .
And in the same shell there are 4d and 4f subshells are vacant. 
In order to forms maximum covalent bonds 3 more vacant orbitals will be used in addition to previous 4 orbitals , Now the number of remaining vacant orbitals are 9 in number.
Regards