Answer
See the detailed answer below.
Work Step by Step
At that time, scientists had not yet discovered quarks, gluons, and other particles that play a crucial role in holding protons together within the nucleus despite the strong repulsive forces between them.
So, scientists considered the presence of electrons between protons as essential to neutralize the repulsive force between them.
Additionally, they thought that the accelerating of the electron was temporary since they thought its path was a vortex around the nucleus, and, eventually, it would hit the nucleus and finally settle inside it.
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