At the particle level, the weakest of the fundamental forces is: gravity electromagnetic forces strong force weak force

GRAVITY

Explanation:

There are four fundamental forces in nature

1). Gravitational force

2). Electromagnetic force

3). Strong Nuclear Force

4). Weak Nuclear Force

So here out of all above forces the strongest force is nuclear force which only depends on the distance between the nucleons while the weakest force among all is gravitational force which depends on the mass of two bodies and distance between them.

Gravitational force is a long range force so it exist upto the large distance while nuclear force is a short range force and could not exist for large distance which is more than 1 fermi.

So here correct answer will be

Gravity

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