Reliability of concepts and approximate parameter values down to about L 10 nm 100 atoms

The large extent of the "classical" range of scaling, from 1mm down to perhaps 10 nm, is related to the stability (constancy) of the basic microscopic properties of condensed matter (conventional building and engineering materials) almost down to the scale I of 10 nm or 100 atoms in line, or a million atoms per cube.

Typical microscopic properties of condensed matter are the interatomic spacing, the mass density, the bulk speed of sound vs, Young's modulus Y, the bulk modulus 5, the cohesive energy UQ, the electrical resistivity p, thermal conductivity K, the relative magnetic and dielectric susceptibilities k and e, the Fermi energy EF and work function cp of a metal, and the bandgap of a semiconductor or insulator, Eg. A timely example in which bulk properties are retained down to nanometer sample sizes is afforded by the CdSe "quantum dot? fluorescent markers, which are described below.

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