The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...
Then in 1869, a Russian scientist called Dmitri Mendeleev produced one of the first practical periodic tables. He wrote the properties of the elements on pieces of card and rearranged them until ...
in an attempt to memorise some of the 118 elements. This year, the periodic table of chemical elements celebrates its 150th birthday. As the candles on the cake are lit, it's time to test your ...