Stars and Nebulae...

Index

Atoms
The Elements
Electron Energy Levels
Light Photons
Atomic Absorption Spectra
Atomic Emission Spectra
Stellar Spectra


The Elements

WebElements.com

There are 92 naturally occurring elements. Another 20, approximately, artificial elements have been created in atomic reactors and accelerators. An element is a substance containing only one type of atom. Hydrogen is the lightest element. Its atoms have only one proton and one electron. Uranium is the heaviest naturally occurring element. Its atoms have 92 protrons and electrons.