C is the answer hope this helps
Answer : The number of iron atoms present in each red blood cell are, 
Explanation :
First we have to calculate the moles of iron.

Now we have to calculate the number of iron atoms.
As, 1 mole of iron contains
number of iron atoms
So, 0.0519 mole of iron contains
number of iron atoms
Now we have to calculate the number of iron atoms are present in each red blood cell.
Number of iron atoms are present in each red blood cell = 
Number of iron atoms are present in each red blood cell = 
Number of iron atoms are present in each red blood cell = 
Therefore, the number of iron atoms present in each red blood cell are, 
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<u>ANSWER</u></h3>
2. Neon, only
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<u>EXPLANATION</u></h3>
When Na and F combine they form an electron configuration of 2-8. Na electron configuration is 2-8-1 while F is 2-7, so when they form an ionic bond F will gain Na outermost electron to complete its valence shell due to having a higher negativity. Neon has an electron configuration of 2-8 but argon has 2-8-8.