The answer I believe is number 1
        
                    
             
        
        
        
~Hello there!
Your question: What name is given to elements with the same number protons but differing  numbers of neutrons?
Your answer: Istopes is the name given to the elements with the same number of protons but differing number and neutrons.
Any queries ^?
Happy Studying!
        
             
        
        
        
Answer:
<em><u>It is a C4 plant 100% sur</u></em>e
hope i helped
-lvr