An approach is described in which accurate weighings are provided under circumstances when samples cannot be placed directly on a balance pan. The approach, based on external weighing, uses a new simple apparatus designed for any kind of analytical balance and not requiring a hole through the base of the balance. (JN)

Discusses a revised and extended version of the Mulliken electronegativities. Describes applications and limitations implied by this version. (CW)

Discusses a revision and extension of the Mulliken electronegativity scale to consider 50 elements. Describes the calculation of valence-state promotion energies and Mulliken atomic electronegativities and the conversion of Mulliken electronegativities to Pauling units. (CW)

Presents a quantitative treatment of ionization potentials of isoelectronic atoms. By looking at the single-electron view of calculating the total energy of an atom, trends in the screening and effective quantum number parameters are examined. Approaches the question of determining electron affinities. (CW)

Described are the energetics involved in the formation of molecular hydrogen using concepts that should be familiar to students beginning the study of molecular orbital theory. Emphasized are experimental data on ionization energies. Included are two-electron atomic and molecular systems. (CW)

Reviews a method for determining oxidation numbers in covalent compounds and balancing mixed organic-inorganic or purely organic systems. Points out ambiguities presented when adjacent atoms have small or zero electronegativity differences. Presents other limitations that arise when using electronegativity values. (CW)