Gravitational force depends on inverse square law. That is, gravitational force is inversely proportional to square of distance between asteroids. As distance between them decreases, gravitational force increases. Hence A is correct.
An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers.Explanation:
The nuclear force is attractive and not repulsive.
The nuclear force is very weak and much smaller in relative magnitude than the electrostatic and gravitational forces.
Explanation:
Nuclear force is the strongest existing force in the nature.
It has the shortest range.
Its main function is to hold the subatomic particles together in nature.
The nuclear force is created by the exchange of pi mesons between the nucleons of an atom, but for this exchange to happen the particles must be close to one another of the order of few femtometer.
At about 1 femtometer the nuclear force is very strongly attractive in nature but at distance greater than 2.5 femtometer it fades away.
The force becomes repulsive in nature at distance less than 0.7 femtometer.
This force holds the likely charged protons together in the nucleus.
