Answer: This is called moles
Explanation: This is described to be the number of molecules, atoms or ions in a substance :)
Answer:
The answer to your question is A.
Pure substances can not be broken down into others, so they cannot be molecules
Explanation:
Answer:
the ionic radius of the anion 
Explanation:
From the diagram shown below :
The anion
is located at the corners
The cation
is located at the body center
The Body diagonal length = 
∴ 
Given that :
(i.e the ratio of the ionic radius of the cation to the ionic radius of
the anion )

Also ; a = 664 pm
Then :

Therefore, the ionic radius of the anion 