Periodic table - Elements, Groups, Blocks | Britannica
https://www.britannica.com/science/periodic-table/The-periodic-table
WEBPeriodic table - Elements, Groups, Blocks: The periodic table of the elements contains all of the chemical elements that have been discovered or made; they are arranged, in the order of their atomic numbers, in seven horizontal periods, with the lanthanoids (lanthanum, 57, to lutetium, 71) and the actinoids (actinium, 89, to lawrencium, 103 ...
DA: 21 PA: 37 MOZ Rank: 100