Answer:
A. a rotten potato gives all of bad smell
Explanation:
B,C,D are all physical changes because we can reverse them back.we can cool the water back to make ice. if the wind passes again we can randomly get the same cloud shape in c. and in d we can make that statue again. but in A can we reverse the rotting process ? ( the enzyme reaction) no we cant because it is a chemical reaction it gives a bad smell because of the chemical changes occuring in it.
hope this helps
 
        
             
        
        
        
Answer:
They will die.
Explanation:
Polar Bears were made to live in the frigid temperatures of the tundras. If there is a temperature change it can affect their habitat. It can destroy it and they would have to move out to another place. They can die due to global warming. 
 
        
             
        
        
        
10g
Explanation:
Box 1, Mass of A = 10g
Box 2, Mass of B = 5g
Box 3, = 1A + 1B
Unknown: 
Mass of B that would combine with mass of 20g of A
Solution: 
    Mass ratio of A to B: 
     = mass ratio
 = mass ratio
             = mass ratio
 = mass ratio
         The mass ratio of A to B = 2: 1 
 Now, number of B that will combine with 20g of A; 
        
             = mass ratio
 = mass ratio
                 =
 = 
                      Mass of B = 10g
10g of B would combine with 20g of A
learn more: 
Rate brainly.com/question/8677367
#learnwithBrainly