As in DNA replication, RNA is synthesized in the 5' â 3' direction (from the point of view of the growing RNA transcript). Only one of the two DNA strands is transcribed. This strand is called the template strand, because it provides the template for ordering the sequence of nucleotides in an RNA transcript.
The properties of the chemical elements are summarized on the periodic table, which organizes the elements by increasing atomic number into rows (periods) in which the columns (groups) share recurring (periodic) physical and chemical properties.
Today, the periodic table organizes the elements in horizontal rows, or periods, by order of increasing atomic number, which equals the number of protons in the atomic nucleus of each element. The elements are also organized in vertical columns, or groups, based on similar physical characteristics and chemical behavior. This arrangement developed side by side with atomic theory over about 200 years, and it continues to evolve as new elements are discovered.