CHAP. 12: BASIC TERMS OF CHEMICAL PHYSICS [CONTENTS] 412
Chapter 12
Basic terms of chemical physics
Chemical physics is an important area of modern physical chemistry embracing theoretical
fields on the boundary between chemistry and physics. Chemical physics describes the studied
system either as a system of macroscopic phases without any further inner structure, or as a
set of elementary particles and the atoms and molecules composed of them, from which the
properties of the whole system are then derived by mathematical procedures. Comparison of
both the above approaches allows for gaining a lot of information both about the system as a
whole and about the properties of the molecules it contains.
12.1 Interaction of systems with electric and magnetic
fields
In addition to the classic thermodynamic quantities such as temperature, volume and pressure,
other system properties need to be defined for systems interacting with the surrounding fields.
12.1.1 Permittivity
The vector of the intensity of the electric field around a point charge following from the
Coulomb lawis
E~=^1
4 πεQ ~r
r^3