How many synthetic elements are on the periodic table?

The periodic table includes 24 elements that are generally considered synthetic, meaning they are produced artificially rather than found in significant natural abundance. This group includes elements such as technetium and promethium, as well as all elements from atomic number 93 upward, many of which are made in particle accelerators or nuclear reactors. Some of these, like neptunium and plutonium, can also occur in tiny natural traces. The superheavy elements at the end of the table are created atom by atom and often exist for only fractions of a second. Their discovery extends the limits of chemistry and nuclear physics.