Answer: chemical 
not 100% sure
        
                    
             
        
        
        
Answer:
N2H2(aq) + 2OH^-(aq) ----------> N2(g) + 2H2O(l) + 2e
Explanation:
Hydrazine is mostly used in thermal engineering as an anticorrosive agent. Hydrazine can be oxidized in aqueous solution as shown in the equation above. Oxidation has to do with loss of electrons and increase in oxidation number.
The oxidation number of nitrogen in the equation increased from -1 in hydrazine on the lefthand side of the reaction equation to zero in nitrogen on the right hand side of the reaction equation. Two electrons were lost in the process as shown.
 
        
             
        
        
        
The variable that stays the same in an experiment is called the controlled variable
Hope this helps
        
             
        
        
        
The third reason helped Rutherford to discover the nucleus.
        
             
        
        
        
Impure substance, because pure would be dirt from the earth