This is not a valid question. Please ask a question to receive an answer. 
 
        
             
        
        
        
Answer:
1)Genus 2)Family 3)Order 4)Phylum 5) Domain
Explanation:
Species is a large group of living organisms that can breed freely among themselves, exchange genes and produce offspring.
Taxonomic rank is the group of living organisms that are related to each other and most basic rank is species. The lower the rank the smaller it be and contain most similar organisms. 
The higher rank comprises by combining of smaller ranks like in your question the family contain many genus and order contain many families and so on. Thatswhy most higher rank would contain maximum number of species.
 
        
             
        
        
        
Answer:
Choice C. Sodium bicarbonate acted as a pH buffer in Solution 2.
Explanation: 
Sodium carbonate is used as pH buffering agent. Buffering agent is a type of solution which contains weak base or acid which stabilize the solution when another strong acid or base is added to the solution. If acid is added, the weak base that is present in the solution reacts with it and when base is added, weak acid reacts with it. 
 
        
             
        
        
        
Answer:
1.a, 2.b, 3. c, 4. c, 5. c
Explanation:
1. 
4H+O2→2H2O 
2.
They must have two or more reactants.
3.
The reaction has more than one product.
4.
S + O2→SO2
5.
2Mg+O2→2MgO