| 
    
        | Engineering  :: Nuclear Engineering |  | 
       
        
	 
	
	 
 |  |  | 
| 
        
     | 
    
  
        | 
            
            
                |  | A radioactive substance gives off Y-rays when |  
                | | [A]. | its nucleus goes from a higher energy state to a lower one | [B]. | one of the orbital electrons jumps from a higher orbit to one of a lower energy |  | [C]. | an orbital electron jumps from a lower orbit to a higher one | [D]. | its nucleus goes from a lower energy state to a higher one | 
 |  |   |  
 
 |  |