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.
Battle of Dunkirk. The Battle of Dunkirk lasted from around May 25 to June 3, 1940. After the Phony War, the Battle of France began in earnest on 10 May, 1940. German armour burst through the Ardennes region and advanced rapidly driving north in the so-called sickle cut.