Concept:The planetary model describes electrons moving in fixed circular paths around a tiny, central nucleus, just as planets move around the sun.
Explanation:Niels Bohr proposed this planetary model of the atom in
1913.
Ernest Rutherford had earlier discovered the nucleus through his gold foil experiment, but his work did not fully explain how electrons are arranged around it.
Bohr improved the atomic model by stating that electrons revolve around the positively charged nucleus in specific circular orbits called energy levels or shells.
His model is therefore called the planetary model because the electrons orbit the nucleus in the same way that planets orbit the sun.
Modern quantum theory later replaced these fixed orbits with probability clouds, but the planetary model itself is credited to Bohr.
Since the question asks for the scientist who proposed the planetary model with electrons orbiting the nucleus, the correct choice is Niels Bohr.
Answer:C. Niels Bohr