The periodic table, also called the periodic table of elements, is an organized arrangement of the 118 known chemical elements. The chemical elements are arranged from left to right and top to bottom ...

The origin of heavy elements in our universe is theorized to be the result of neutron star collisions, which produce conditions hot and dense enough for free neutrons to merge with atomic nuclei and ...

Nineteen elements on the periodic table — including gold, cadmium, arsenic and aluminum — are getting their atomic weights adjusted. The International Union of Pure and Applied Chemistry (IUPAC) ...

Standard atomic weights, those numbers emblazoned under the elements on the periodic table, were once thought of as unchanging constants of nature. But researchers have tweaked the atomic weights of ...

Four new elements joined the periodic table in 2016. These superheavy elements only exist for seconds at a time before they decay, making it hard for scientists to pin down their properties.

At the middle of the 19th century, 63 chemical elements were known to science. Before Mendeleev’s discovery, attempts at arranging them in some logical way were made by Johann Doebereiner (1829), ...