So as two objects are separated from each other, the force of gravitational attraction between them also decrease. if the separation distance between 2 objects is doubled (increased by a factor of 2), then the force of gravitational attraction is decreased by a factor of 4 (2 raised to the second power).
Hope this helps :)
Answer:
No. of Molecules = 18.06 x 10²³ molecules
No. of Atoms of P = 3 atoms
No. of Atoms of Na = 9 atoms
Total No. of Atoms = 24 atoms
Explanation:
<u>FOR NUMBER OF MOLECULES</u>:

<u>No. of Molecules = 18.06 x 10²³ molecules</u>
<u></u>
<u>FOR NUMBER OF P ATOMS</u>:

<u>No. of Atoms of P = 3 atoms</u>
<u></u>
<u>FOR NUMBER OF Na ATOMS</u>:

<u>No. of Atoms of Na = 9 atoms</u>
<u></u>
<u>FOR TOTAL NUMBER OF ATOMS</u>:

<u>Total No. of Atoms = 24 atoms</u>
<u></u>
<u></u>
D. Screw is the answer to your question
They are the standard system used by scientists worldwide, and
officially by almost all nations of the world. So if you describe a
measurement in terms of SI units, there's less chance that you'll
need to explain the measurement to anyone who reads it ...
most scientists and common people worldwide will understand
what your number means.
B I think for 19 and D for 20