# Atomic Structure

- Page ID
- 127064

- 98: A de Broglie-Bohr Model for Positronium
- Positronium is a metastable bound state consisting of an electron and its positron antiparticle. In other words it might be thought of as a hydrogen atom in which the proton is replaced by a positron. Naturally it decays quickly after formation due to electron-positron annihilation. However, it exists long enough for its ground state energy to be determined. The purpose of this tutorial is to calculate this value using the Bohr model for positronium.

- 106: Atomic Stability
- The issue of atomic stability will be explored with a quantum mechanical analysis of the two simplest elements in the periodic table - hydrogen and helium. Schrödinger's equation can be solved exactly for the hydrogen atom, but approximate methods are required for the helium atom. However, in the pursuit of an explanation for atomic stability, it is instructive to use an approximate method to study the hydrogen atom.

- 121: A Bohr Model for Multi-electron Atoms and Ions
- A deBroglie Bohr model is described that can be used to calculate the electronic energies of atoms or ions containing up to four electrons. Seven exercises are provided which can be used to give students training in doing energy audits, carrying out simple variational calculations and critically analyzing the calculated results.

- 132: Calculating the Atomic Radius of Polonium
- Three experimental facts are required to determine the atomic radius of a metallic element such as polonium: (1) density, (2) molar mass and (3) crystal structure.

*Thumbnail: Depiction of a hydrogen atom with size of central proton shown, and the atomic diameter shown as about twice the Bohr model radius (image not to scale). (Public Domain; Bensaccount).*