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 as basic letters following "c" and "l", respectively. "Ch" and "ll" are still considered letters, but are now alphabetized as two-letter combinations. (The new alphabetization rule was issued by the Royal Spanish Academy in 1994.) On the other hand, the digraph "rr" follows "rqu" as expected, and did so even before the 1994 alphabetization rule. In a few cases, such as Kiowa, the alphabet has been completely reordered. Alphabetization rules applied in various languages are listed below. Collation algorithms (in combination with sorting algorithms) are used in computer programming to place strings in alphabetical order. A standard example is the