The Bohr Model of the Atom

Introduction

• The Bohr model, named after Danish physicist Niels Bohr, provides a simplified representation of the structure of an atom.
• It introduces the concept of energy levels and orbits for electrons within an atom.

Components of the Bohr Model

• In the Bohr model, an atom consists of the following components:
  • A small, positively charged central nucleus at the core.
  • Electrons that orbit the nucleus at specific, fixed distances from the nucleus.
  • These fixed electron orbits are often referred to as energy levels or electron shells.

Fixed Energy Levels

• Electrons in the Bohr model are not allowed to exist in the spaces between these specific fixed orbits.
• Each electron orbit or energy level corresponds to a specific energy state for the electron.
• The diagram depicts the allowed orbits and energy levels for a hydrogen atom, a fundamental example.

Energy Levels

• The lowest energy level, closest to the nucleus, is referred to as the ground state.
• When an electron absorbs energy, it can transition to a higher energy level, known as an excited state.
• If an electron gains sufficient energy to be completely removed from the atom, it is said to be in an ionised state.

Significance

• The Bohr model helped explain the discrete spectral lines observed in the emission and absorption spectra of hydrogen.
• It provided a basis for understanding the quantisation of energy levels in atoms.

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The Bohr Model of the Atom

Limitations

• While the Bohr model was groundbreaking, it is a simplified model and does not fully account for the complexities of electron behaviour in atoms.
• It was later replaced by more sophisticated quantum mechanical models, such as the Schrödinger equation, which provides a more accurate description of atomic structure.