Answer:
It going to be confusing to see 10 skyscrapers that look the same and hard to go to the right one 
Explanation:
 
        
                    
             
        
        
        
Ground state of Al  is 1s²2s²2p⁶3s²3p¹.
Exited state of Al is 1s²2s²2p⁶3s¹3p².
        
                    
             
        
        
        
You can eliminate A, C, and D almost instantly if you know that engineers are construction workers. The answer is B.
        
                    
             
        
        
        
Answer:
Ag+
Explanation:
If you imagine as if the problem were double replacement, you would pair the Cl with one of the following ions provided in the choices. As seen on Table F, Ag+ paired with Cl- produces an insoluble compound, hence the precipitate. All the other ions shown in the multiple choice section, when paired with Cl- will produce a soluble compound, as a result NOT a precipitate.