Here's why:
* Atoms are mostly empty space: The vast majority of an atom's volume is empty space. The nucleus, containing protons and neutrons, is extremely small compared to the overall size of the atom.
* Electrostatic repulsion: The electrons surrounding the nucleus have a negative charge. When atoms approach each other, the electrons in their outer shells repel each other due to their like charges. This electrostatic repulsion is what prevents atoms from interpenetrating.
While the strong nuclear force plays a role in holding the nucleus together, it doesn't directly contribute to preventing objects from passing through each other. The strong force is very short-range and acts primarily within the nucleus, not between atoms.
It's important to note that there are some special circumstances where objects can appear to pass through each other:
* Quantum tunneling: This is a phenomenon where particles can pass through barriers that they should theoretically be unable to overcome due to their energy. It occurs at the quantum level and is significant in areas like nuclear fusion and certain electronic devices.
* Superfluidity: In this state of matter, particles have zero viscosity and can flow without resistance. In superfluid helium, for example, atoms can pass through each other without colliding.
However, in everyday life, the electromagnetic force is the primary reason why objects don't pass through each other.
