W=(m'/m)·100%
m'=37.2 g
m=48.5 g
w=(37.2/48.5)·100%=76.7%
        
                    
             
        
        
        
Answer:
One atom lf helium has a mass of 4 u 
Know that 1 u =1.66. 10-24g
 
        
             
        
        
        
Answer:
its none above
Explanation:
food webs have arrows that show the flow of energy from one orhganism to the next
 
bar graphs have bars and numbers and diagrams have words and pictures so it D
 
        
                    
             
        
        
        
Answer:
0.0102 L or 10.2 mL 
Explanation:
From the question given above, the following data were obtained:
Molarity = 0.250 M
Mole = 0.00255 mole
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole / Volume
With the above formula, we can obtain the volume as follow:
Molarity = 0.250 M
Mole = 0.00255 mole
Volume =?
Molarity = mole / Volume
0.250 = 0.00255 / volume 
Cross multiply
0.250 × volume = 0.00255
Divide both side by 0.250
Volume = 0.00255 / 0.250
Volume = 0.0102 L
Covert 0.0102 L to mL. 
1 L = 1000 mL 
Therefore, 
0.0102 L = 0.0102 L × 1000 / 1 L 
0.0102 L = 10.2 mL 
Thus, the volume is 0.0102 L or 10.2 mL