Answer:
We have to add 9.82 grams of calcium acetate
Explanation:
Step 1: Data given
Molarity of the calcium acetate solution = 0.207 M
Volume = 300 mL = 0.300 L
Molar mass calcium acetate = 158.17 g/mol 
Step 2: Calculate moles calcium acetate 
Moles calcium acetate = molarity * volume
Moles calcium acetate = 0.207 M * 0.300 L 
Moles calcium acetate = 0.0621 moles 
Step 3: Calculate mass calcium acetate 
Mass calcium acetate = moles * molar mass
Mass calcium acetate = 0.0621 moles * 158.17 g/mol
Mass calcium acetate = 9.82 grams
We have to add 9.82 grams of calcium acetate
 
        
             
        
        
        
Although birds' eggs appear to be fragile, they are in fact extremely robust. The oval shape applies the same rules of engineering as an arched bridge; the convex surface can withstand considerable pressure without breaking.
 
        
             
        
        
        
Here are the resonance contributors I found.
 
        
             
        
        
        
Answer:
The answer to your question is letter D. 2.02 g
Explanation:
Data
moles of Ne = 0.100
atomic mass of Neon = 20.18 g
Process
1.- Use proportions to find the answer
                    20.18 g of Ne ------------------  1 mol of Ne
                         x                 ------------------  0.1 moles
                         x = (0.1 x 20.18)/1
                         x = 2.018
2.- Consider the significant figures
       0.100 has three significant figures so the answer must be  2.02 g