The electrons surrounding an atom are located in regions around the nucleus called “energy levels”. An energy level represents the 3-dimensional space surrounding the nucleus where electrons are most likely to be. The first energy level is closest to the nucleus.
 
        
                    
             
        
        
        
Antibiotics germs killed immune system in the human body
        
                    
             
        
        
        
Answer:
C
Explanation:
I searched it online and it confirms my notes too
 
        
             
        
        
        
I'm not exactly sure, but i would guess the noble gasses. The reason for this is that the noble gasses are stable. There outer shells are completely full. That means they have the same number of electrons.