Interaction between atoms by which they “share” Charge on an ion reflecting gained or lost electrons. For example, an iron atom that has lost two electron, Fe2+, is described as having a valence of 2. Typical valences in geological materials are shown below. electrons in the outermost energy shells, thereby filling the outer shell of both atoms involved in the interaction. This occurs between atoms with similar high electronegativities (ΔX~0), resulting in highly localized bonding orbitals. For example, each Lightest and most common element in the universe (~92% by atoms; ~75% by mass). Hydrogen's isotopes are: • 1H (99.9885 %)
• 2H (0.0115 %), also called deuterium.
• 3H, also called Tritium, is a radioactive (t½ = 12.32 y) by-product of atmospheric thermonuclear tests in Earth's hydrosphere and atmosphere.
atom in a hydrogen gas Collection of atoms held together by chemical bonds into a discrete, finite structure. One way molecules are represented is by a chemical formula where symbols for the elements are used to indicate the types of atoms present and subscripts are used to indicate the relative numbers of atoms. For example, has a single electron. The valence energy level of a hydrogen atom is filled by two electrons; sharing their electrons allows each hydrogen atom to fill its energy shell.
Some or all content above used with permission from J. H. Wittke.