Answer:metres
Explanation:It would be best to measure the length of an object in metric system such as millimeter, centimeter, mere etc.. 
 
        
                    
             
        
        
        
Answer:
A 
Explanation:
The purpose of the periodic table was to organize elements as they were discovered into periods and groups, according to their properties. It was not just a naming of elements, as a list. 
 
        
             
        
        
        
Explanation:
1 mol = 22.4 l
5.42 mol = 22.4 × 5.42 = 121.408
in two decimal place it is 121.41
 
        
             
        
        
        
The answer would be the last one- it separates dissolved substances.
Have a great rest of your day!