There are 115 known elements as of today (Feb. 13, 2016)
so, 'C' is the correct answer
        
                    
             
        
        
        
The lithosphere is the solid, outer part is the earth it includes the brittle upper portion of the mantle and the crust and the outermost layers of Earths structures
        
             
        
        
        
Probably sodium Na because it has a similar atomic mass and number
        
             
        
        
        
It is mostly about an element, it usually goes like this: "which element has the bigger atomic size, Sodium or Oxygen? " 
        
             
        
        
        
Answer: B. Hydrolysis (adding water)
Explanation:
When peptide bonds join two or more amino acids together, this is refered to as a peptide. A polypeptide simply means several amino acids. We should also note that proteins contains polypeptides. 
The reaction that is capable of breaking polypeptides into their component amino acids is hydrolysis. This simply means a chemical process whereby a water molecule is being added to a particular substance.