Pictorial periodic table. The periodic table shows the chemical elements ordered by atomic number (number of protons in the nucleus), but arranged in rows (periods) so that elements with similar chemistry occur in the same vertical column (group). The standard periodic table has 118 elements arranged in 18 groups and 7 periods. Here, each element is represented by its chemical symbol and an image. Above each symbol is the element's atomic number, and below it is the element's name. The lathanoids and actinoids are expanded at bottom. This periodic table uses the standard names and data published by IUPAC (the International Union of Pure and Applied Chemistry) in 2005. Elements 113 to 118 have yet to be fully authenticated and have temporary names.