erivatives of the hydrocarbons are formed, by replacing one or more hydrogen atoms by other groups referred to as functional groups An alcohol is closely related to a hydrocarbon in that it contains an Oh group in place of a hydrogen atom. Thus, methyl alcohol, CH3 OH, is a derivative of methane, CH4; and ethyl alcohol
Why one needs statistics for describing physical phenomena? Any measurable macroscopic property is an average over a very huge number of microscopic configurations. Time scale of thermal fluctuations and basic relaxations~fs(femto second, 10-15 second). During the time interval necessary for realizing a measurement, a macroscopic system undergoes the change of its microscopic configuration for many many times!
Forces on a Wire Carrying a Current in a Magnetic Field Magnetic Pressure Magnetic Energy Denisity Magnetic Forces btwn Two Electric Currents Magnetic Forces Within an Isolated Circuit