To effect an increase in the gravitational force between two objects, the mass of both objects should be increased and the distance between them reduced.
This is derived from the Newton's law of universal gravitation:
It states that "the force of gravity between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them".
Therefore, if the mass of the two bodies are increased and the distance between them reduced, the gravitational force of attraction will increase.
This is because all noble gases haves full outer shell therefore they don’t participate in bonding.They are referred to as inert which means unreactive.