Periodic table it is relatively easy to predict the chemical properties of an element if one knows the properties of the elements around it. , the periodic table has 118 confirmed elements, from element 1 (hydrogen) to 118 (oganesson). Elements 113, 115, 117 and 118, the most recent discoveries, were officially confirmed by the International Union of Pure and Applied Chemistry (IUPAC) in December 2015. Their proposed names, nihonium (Nh), moscovium (Mc), tennessine (Ts) and oganesson (Og) respectively, were announced by the IUPAC in June 2016 and made official in November 2016. The first 94 elements occur naturally; the remaining 24, americium
Extended periodic table chemically active. Its chemical behaviour is expected to be similar to uranium and neptunium, as further ionisation past the +6 state (corresponding to removal of the 6g electrons) is likely to be unprofitable; the +4 state should be most common in aqueous solution, with +5 and +6 reachable in solid compounds. The number of physically possible elements is unknown. A low estimate is that the periodic table may end soon after the island of stability, which is expected to center on "Z" = 126, as the extension of the periodic and nuclides tables is restricted by the proton and the