Technically, the answer should be 3.30 * 10^23 grams. But I think you mean either molecules, atoms, moles or grams of Ni2I6 with that number of molecules .
1 mole of Ni2 I6 = 6.02 * 10^23 molecules
x [mole] = 3.30 * 10^23 molecules
1/x = 6.02 * 10^23 / 3.30 * 10^23 Cancel the 10^23 on the right side
1/x = 6.02 / 3.30 Cross multiply
3.30 = 6.02 x Divide by 6.02
3.30 / 6.02 = x
x = 0.548 moles
what to do from here?
1 mole of Ni2I6 is
2 * Ni = 2 * 59 = 118 grams
6 * I = 6 * 131 = <u>786 grams</u>
Total = 904 grams
Set up a proportion.
<u>1 mole Ni2I6 </u> = <u>904 grams</u>
0.548 moles = x
1/0.548 = 904/x Cross multiply
x = 0.548 * 904
x = 495.4 grams of Ni2I6 <<<<<< Answer.
If you cross a heterozygous organism with another heterozygous organism, pair two Tt and Tt. Below is a punnet square to show the result:
T t
T TT Tt
t Tt tt
This means that you have two heterozygous recessive and one homogenous dominant and one homogenous recessive.
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, 