Am I right in giving the following reason for some questions relating to the p-block?

1. I'm seeking clarification as I believe this to be the answer to why boron compounds are electron deficient.
While bonding, the $2s^2$ electrons of Boron are excited to the $2p\_y$ orbital, they engage in bonding. However, even after bonding, there exists an empty $2p\_z$ which leaves an incomplete shell, thus these compounds require two more electrons and so, they are electron deficient.
(As in the case of $\ce{BCl3}$)
2. $\ce{CO2}$ cannot put out fire caused by the reaction of saline hydrides and water as it will be converted into formate ions during the process. (although, I'd appreciate some help on chemical equations if possible)


Moreover, if this is accurate, does the same logic apply to $\ce{NH3}$? 


Grade 11. 


