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.
Belleau Wood Campaign. The Battle of Cantigny, fought on 28 May 1918 was the first American offensive of World War I. The U.S. 1st Division, the most experienced of the seven American divisions then in France and in reserve for the French Army near the village of Cantigny, was selected for the attack.