Draw and determine the hybridization and unhybridized orbitals for the following covalent compound. 
KrBr₄                                                                                       Hybridization:   
                                                                                               Unhybridized Orbitals:

How many of the following molecules have sp³d² hybridization on the central atom? 

SeCl₆                            XeCl₄                           IF₅                               AsCl₅

How many unhybridized orbitals does the beryllium atom possess in BeCl₂?

The orbital diagram that follows presents the final step in the formation of hybrid orbitals by a silicon atom. (b) What type of hybrid orbital is produced in this hybridization?