During the past decades, a considerable progress in plasma applications has been made such as cutting, spraying, arc heating, re-entry of space-vehicles, astrophysical problems. All these applications require the knowledge of thermodynamic and transport properties of hydrogen and argon-hydrogen plasmas. The evaluation of transport properties of thermal plasmas is based upon solving the Boltzmann equation using the Chapman-Enskog method. The present work in the form of a book is useful to realize and estimate the role of Electronically Excited States(EES) in affecting the transport properties for LTE hydrogen, argon and argon-hydrogen plasmas. The thermodynamic properties of given plasma are function of degree of ionization, which is usually obtained using the Saha equation. The role of EES in affecting these properties has been examined over wide range of temperature and pressure. The thermodynamic and transport properties of argon and argon-hydrogen plasmas have been calculated for both GS and ES plasmas under LTE conditions over a wide range of temperature and pressure.