The internal energy and temperature of a system decrease (E E. The System and Work. The system is usually defined as the chemical reaction and the boundary is the container in which the reaction is run. In the course of the reaction, heat is either given off or absorbed by the system.
The Middle Ages began in the year 476 A.D. and ended around 1300 with the beginning of the Renaissance. The Middle Ages, also called the Medieval Period, began just after the fall of Rome and it dominated the European continent through the early 14th century. The Middle Ages filled a time period between the ending of a great reign and the beginning of a new era characterized by revitalization and cultural growth.
The Middle Ages. The traditions of Western music can be traced back to the social and religious developments that took place in Europe during the Middle Ages, the years roughly spanning from about 500 to 1400 A.D.