Question

Lists how many valence electrons are shared, gained, or lost by each atom of the 6 compounds?      
N2          
CCl4            
SiO2          
AlCl3            
CaCl2        
LiBr          

Answer 1

Nitrogen is bonded with another nitrogen atom via a triple bond. Therefore it shares 3 electrons.
Carbon forms 4 covalent bonds and it is attached with one Cl atom via a single bond. Therefore 4 electrons are shared in this compound.
Si also shares 4 electrons in the given compound as the arrangement in this molecule is tetrahedral.
Al donates 3 electrons and Each Cl atom gain one electron to form AlCl3.
Ca donates 2 electrons and 2Cl atoms gain 2 electrons to form CaCl2.
In LiBr, Li donates one electron and Br accepts one electron.