Block (periodic table) the s-block, with its outer (and only) electrons in the 1s atomic orbital, although its chemical properties are more similar to the p-block noble gases due to its full shell. In addition to the blocks listed in this table, there is a hypothetical g-block which is not pictured here. The g-block elements can be seen in the expanded extended periodic table. Lanthanum and actinium are placed under scandium and yttrium to reflect their status as d-block elements, as they have no electrons in the 4f and 5f orbitals, respectively, while lutetium and lawrencium do. The s-block is on the left
Alphabetical order Festus wrote an encyclopedic epitome of the works of Verrius Flaccus, "De verborum significatu", with entries in alphabetic order. In the 3rd century CE, Harpocration wrote a Homeric lexicon alphabetized by all letters. In the 10th century, the author of the "Suda" used alphabetic order with phonetic variations. In the 14th century, the author of the "Fons memorabilium universi" used a classification, but used alphabetical order within some of the books. In 1604 Robert Cawdrey had to explain in "Table Alphabeticall", the first monolingual English dictionary, "Nowe if the word, which thou art desirous to finde, begin with (a) then