atoms are indeviscible then what about nuclear reactors where they divide the atom
‘Fission’ is another word for splitting. The process of splitting a nucleus is called nuclear fission. Uranium or plutonium isotopes are normally used as the fuel in nuclear reactors because their nuclei are relatively large and easy to split.
For fission to happen, the uranium-235 or plutonium-239 nucleus must first absorb a neutron. When this happens:
1) The nucleus splits into two smaller nuclei
2) Two or three neutrons are released
3) Some energy is released
The additional neutrons released may be absorbed by other uranium or plutonium nuclei, causing them to split. Even more neutrons are then released, which in turn can split more nuclei. This is called a chain reaction. The chain reaction in nuclear reactors is controlled to stop it going too fast.
So, actually atom is not dividing, just a single neutron splits a large nucleus.