Answer:
A)Chlorine and Bromine:
They are both non metal hence they form a covalent bond due to covalent bonding.
B)Potassium and Helium:
Helium ion has a small cationic radius and distorted by the potassium ion due to polarization.
C)Sodium and Lithium:
Both are metals hence they form a metallic bond since they share electrons to the electron cloud.
Answer:
The answer is partial charge 8+.
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, 
Answer : 1.12 grams
Yo find the mass of the sample, you take the increased mass and subtract the original mass.
6.130 - 5.010 = 1.12
D. due to the the water it will bring sand with the water there for us is D.