Here I come and we wanna go home!!!
Answer:
If the distance is doubled, the force of gravity between the two bodies is one-fourth as strong as before
Explanation:
The force of gravity between two bodies depends on the mass and distance. But we will focus on distance since that's what the question asks
Therefore, the force of gravity decreases as distance between the bodies increases.
Since the diameter of helium atom is approximately 
, therefore the diameter of helium atom in nano meter,
