Lewis acids and bases Lewis acids and bases A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane (MeB) is a Lewis acid as it is capable of accepting a lone
CSX milepost prefixes Also, like the ACL, the SAL mainline ran from Richmond, Virginia to Tampa, Florida. The S Line is today discontinuous and segments of the original line have been abandoned (notable abandoned segments are between Chester, Virginia and Norlina, North Carolina, and between Riceboro and Seals, Georgia. The Seaboard main line from Richmond to Tampa, heart of its 2600-mile system in 1900, had been built by the following companies: CSX milepost prefixes Most CSX railroad lines are given lettered prefixes before milepost numbers. These prefixes are one to three letters long with the first letter usually refer to the former company.