For more than 90 years, researchers around the world have relied on the CRC Handbook of Chemistry and Physics for authoritative, up-to-date data. This year will be no exception. New tables, extensive updates, and added sections mean the Handbook again sets a new standard for reliability, utility, and thoroughness. New tables in this edition include: Proton Affinities, Electron Inelastic Mean Free Paths, Selected Properties of Semiconductor Solid Solutions, and Vapor Pressures (Solvent Activities) for Binary Polymer Solutions. Sections substantially revised and updated include NIST Atomic Transition Probability Tables, Summary Tables of Particle Properties, and Threshold Limits for Airborne Contaminants. The 86th Edition also marks a fresh look for the Handbook. A larger format and new layout makes it easier to read and a new typeface makes the tables and diagrams crystal clear.