Active is more active which means it's in person
        
                    
             
        
        
        
Answer: The correct option is option d
Explanation - The mean deal with science is that it allows people to carry on research in an organized manner to find or make new discoveries and inventions.  
The basic purpose of science is to try new things or ways to get an outcome by constant perseverance on research and negating the ways that don't work thus giving and improving knowledge of what is correct and what is not to make a new Discovery or invention.  
 
        
                    
             
        
        
        
Answer:
Sprinkling of powder on the carom board <u>reduces</u> friction.
 
        
                    
             
        
        
        
Answer:
Ozone is good in the stratosphere because it absorbs all of the most energetic ultraviolet radiation (UV-C), most of the UV-B radiation and some of the least energetic UV radiation (UV-A). Ozone is “bad” in the troposphere because it is harmful to breathe and is the primary component of smog in summer.
 
        
             
        
        
        
Answer:
in a chemical reaction of NaOH with H2O, after NaOH is completely disassociated, we will find Na+ and OH- ions in the solution. (option C).
Explanation:
In a reaction where NaOH is added to H2O.
NaOH is considered a strong base, this means that in an aqueous solution ( in water) it's  able to completely disassociate in ions. 
There will not remain any NaOH in the solution. This means option D is not correct.
The ions in which NaOH will disassociate are : NaOH → Na+ + OH-
These ions we will find in the solution. 
Not only Na+ because NaOH is a strong base, so there will be a lot of OH- ions as well in solution.
This means in a chemical reaction of NaOH with H2O, after NaOH is completely disassociated, we will find Na+ and OH- ions in the solution.