It would be the fossils amount of mineral acidity im pretty sure!
        
             
        
        
        
Answer:
Hydrogen
Explanation:
If you combine the atoms of H2 and H5, you get 7
 
        
             
        
        
        
<h2>Tropomyosin</h2>
Explanation:
This protein is most likely:  Tropomyosin.
Sacromere is the structural unit of myofibrils i.e. the fibres of the muscles. 
Tropomyosin is the muscle protein that function in contraction of muscle filaments.They are arranged laterally along the myofilament. When the researcher is observing the sacromere, she is observing the muscle fibre.  So, the protein that lines the periphery along the thin filament is more likely to be tropomysin.
 
        
        
        
I believe the answer is B because carbon can easily form chains to bond together.
 
        
             
        
        
        
Answer: important because it helps make sure no one will get hurt 
Explanation:
if there weren't lab rules then people could burn themselves or get severely hurt