0.250 L*3M=0.250 L*3mol/L= 0.750 mol
In sodium there are 11 electrons
In chlorine there are 17 electrons
There are 17 protons in chlorine
There are 11 protons in sodium
I’m not sure what an octet is I study in a British system if there’s anything else you’re not sure of search the Internet it has all the answers
In every reaction, mass cannot be destroyed nor created as defined by the law of conservation of mass. Energy also cannot be destroyed when a chemical reaction takes place