Atoms of non-metal elements gain electrons in some of ... See the study guide on groups in the periodic table for more information.

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

Both rubies and emeralds are minerals, which is a type of rock with a consistent chemical composition and a highly ordered ...

Meyer was just four years older than Mendeleev, and produced several Periodic Tables between 1864-1870. His first table contained just 28 elements, organised by their valency (how many other atoms ...

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 ...

4th Period: Potassium and Calcium—Electrons go into the fourth energy level. A small piece of sodium metal is placed in water. The sodium reacts with the water and gets very hot, producing sodium ...

One feature of compounds made with transition metals is their intense colour. There are many examples in nature, including ...