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 ...

The colors of rubies and emeralds are so striking that they define shades of red and green – ruby red and emerald green. But ...

Ram Mohan looks at how bismuth — a remarkably harmless element among the toxic heavy metals in the periodic table — has sparked ... the German word 'wismuth' (white mass).

The green chemistry principle of atom economy applies to chemical reactions, and minimizes waste down to the molecular level. This exercise uses molecular models to calculate atom economy for a ...