It's not accurate to say that an atom has a "shelled nature" in the way we typically think of shells. The modern understanding of atomic structure is more complex than a simple shell model.

Here's a breakdown of how our understanding of atomic structure developed:

* Early models:

* Dalton's Atomic Theory (1803): Proposed that atoms are indivisible and fundamental building blocks of matter.

* Thomson's Plum Pudding Model (1904): Proposed that atoms are spheres with positive charge and negatively charged electrons embedded within.

* Rutherford's Gold Foil Experiment (1911): This experiment showed that atoms have a dense, positively charged nucleus at their center.

* Bohr Model (1913): Proposed that electrons orbit the nucleus in specific, quantized energy levels, like planets orbiting the sun. This model introduced the concept of electron shells.

* Quantum Mechanical Model (1920s): This model, based on quantum mechanics, is the most accurate model we have. It describes electrons as occupying orbitals, which are regions of space around the nucleus where the probability of finding an electron is high. These orbitals are grouped into electron shells.

Therefore, it's not correct to say that any single person "discovered" the shelled nature of the atom.

Here's a more accurate statement:

* The Bohr model introduced the concept of electron shells, providing a simplified explanation of the quantized energy levels of electrons in an atom.

* The quantum mechanical model further refined this concept, showing that electrons occupy orbitals within shells, and their behavior is governed by quantum principles.

Let me know if you have any other questions.