Answer:
Polystyrene is a versatile plastic used to make a wide variety of consumer products.
Explanation:
 
        
                    
             
        
        
        
Answer:
220.42098 amu
Explanation:
(220 .9 X  .7422) + (220 X .0.1278) + (218.1 X 0.13) =     220.42098 amu
These are weighted averages. 
 So, we will take mass of one and multiply by abundance percentage that is provided and add them together.
In order to calculate the  average atomic mass, we have to convert the percentages of abundance to decimals. So, you get
(220 .9 X  .7422) + (220 X .0.1278) + (218.1 X 0.13) =     220.42098 amu
 
        
             
        
        
        
Answer: the correct answer is : too many fish caused an imbalance in the ecosystem, so the food web was affected.
Explanation: