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 ...

The periodic table was arranged by atomic mass ... the graph showed a perfect straight line. He’d found a way to actually measure atomic number. When the First World War broke out, Moseley turned down ...

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

On the periodic table, metals are found on the left and in the middle, and non-metals are on the right. A zig-zag line divides them. In most periodic tables hydrogen (H) is shown separately but is ...

For the last fifty or so years, the periodic table has been incomplete. Elements after uranium on the periodic table have been synthesized for the past few decades, but there were always a few ...

This puzzle shows many of the elements used to make transistors. The finished puzzle is a section of the periodic table, so the numbers on each tile are their atomic numbers - that means they ...

This year marks the 150th anniversary of the publication of Mendeleev’s Periodic Table of Chemical Elements in 1869. In celebration, the United Nations Educational, Scientific, and Cultural ...