Hopefully this will help and it's what you are looking for.
 
        
        
        
Did you actually join Brainly? You have to sign up to answer questions
        
             
        
        
        
Answer:
any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the nucleus, or different atomic weights. There are 275 isotopes of the 81 stable elements, in addition to over 800 radioactive isotopes, and every element has known isotopic forms. Isotopes of a single element possess almost identical properties.
Explanation:
 
        
                    
             
        
        
        
The protists belong to the kingdom Protista that comes under the domain Eukarya. Protists are a very broad group, comprising of various eukaryotes that do not fit into the other kingdoms, like animals, plants, and fungi. The protists were the initial eukaryotes.  
They would go on to become the precursors for each of the other eukaryotic kingdoms. By examining protists one can witness the transformation between the single-cell prokaryotes and modern multicellular eukaryotes.  
 
        
             
        
        
        
Infancy, you grow from microscopic to a baby size in 9 months which is the fastest you ever grow.