Answer: Nuetrons, protons, electrons, elements and compounds
Explanation: Atoms are the smallest components of matter and it is comprised of these three subatomic particles; nuetrons, protons and electrons. Next in the order are the elements (found in periodic table). Elements are made of atoms and compounds are large molecules made of elements. Elements are pure substances that cannot be broken down into smaller substance by chemical reactions whereas compounds can be broken down further. 
 
        
             
        
        
        
A virus structure can be  on of the following: icosahedral, enveloped,  complex and helical. These viruses can appear to in a shape but a closer, more steady look reveals that they are actually icosahedral.
 
        
             
        
        
        
Kingdom because there are 3 kingdoms - Eukarea, Prokarya and Archaea
        
             
        
        
        
Temperature is considered an biotic limiting factor. The correct answer is A.