Elements in the periodic table are grouped as metals, metalloids or semimetals, and nonmetals. The metalloids separate the metals and nonmetals on a periodic table. Also, many periodic table have a stair-step line on the table identifying the element groups.
World War I. First Battle of the Marne begins. On September 6, 1914, some 30 miles northeast of Paris, the French 6th Army under the command of General Michel-Joseph Manoury attacks the right flank of the German 1st Army, beginning the decisive First Battle of the Marne at the end of the first month of World War I.
By the next day, the counterattack was total. More than two million soldiers fought in the Battle of the Marne, and 100,000 of them were killed or wounded. On September 9, the exhausted Germans began a fighting retreat to the Aisne River.