The Answer is A
This is because sodium needs to give off one electron to be stable, form these options the only element that needs to take one electron to be stable is fluorine thus A is the answer
In the question, the number of atoms per unit cell is required for:
A) Polonium (Po)
In polonium, the structure is simple cubic, meaning there are 8 corner atoms, which add up to one atom per unit cell.
B) Manganese (Mn)
The structure of the Mn can be considered to be a body centered cubic (BCC) and the number of atoms for this is 8 corner atoms and 1 central atoms, making a total of 2 atoms per unit cell.
C) Silver (Ag)
Silver has a face centered cubic (FCC) unit cell structure, where there are 8 corner atoms and 6 atoms on the faces, so there are a total of 4 atoms per unit cell.
We will see that the volume of the unit cell is 144,070,699.06 pm^3
<h3>
How to get the volume of a body-centered cubic unit cell?</h3>
In a body-centered cubic unit cell, the side length of the cube is given as:

Where R is the radius of the atom.
And the volume of a cube is the side length cubed, then we can see that the volume of our cube will be:

Solving that we get:

This is the approximated volume of the unit cell.
If you want to learn more about unit cell structures, you can read:
brainly.com/question/13110055
Minerals, Because when wind blows everything and crushes rocks into minerals.
Please make me brainy answer
The first reason to repeat experiments is simply to verify results. Different science disciplines have different criteria for determining what good results are. Biological assays, for example must be done in at least triplicate to generate acceptable data. Science is built on the assumption that published experimental protocols are repeatable.
2) The next reason to repeat experiments is to develop skills necessary to extend established methods and develop new experiments. “Practice make perfect” is true for the concert hall and the chemical laboratory.
3) Refining experimental observations is another reason to repeat. Maybe you did not follow the progress of the reaction like you should have.
4) Another reason to repeat experiments is to study and/or improve them in way. In the synthetic chemistry laboratory, for example, there is always a desire to improve the yield of a synthetic step. Will certain changes in the experimental conditions lead to a better yield? The only way to find out is to try it! The scientific method informs us that it is best to only make one change at a time.
5) The final reason to repeat an extraction, chromatographic or synthetic protocol is to produce more of your target substance. This is sometimes referred to scale-up.