Science Fair
Batteries come in many shapes and sizes. Some are no larger than a pill while others are heavy and huge size, but most batteries have one thing in common. They store chemical energy and change it into electrical energy. The cell is the basic unit producing electricity. A battery has 2 or more cells, but people often use the world battery when talking about a single cell, too, like a dry cell. One of the most popular batteries that have a cell is a dime sized battery which we use for watches. Cells force electrons to flow along conductors.(DK Science 150). "The electrical force of a cell or battery is called its electromotive force (emf). This force, which makes electrons flow around a circuit, is measured in units called volts (v). Each king of cell has a particular emf. A dry cell, for example, has an emf of 1.5volts." (DK science 150) The other way to measure a battery is by how much current it can provide. Current is used to measure how many electrons flow through the cell and amp is the basic unit for current. There are lots of important parts for regular batteries. They are the positive terminal and electrode, the negative terminal and electrode, and the electrolyte which is located between the two electrodes. The positive electrode is made out of a carbon rod. Powdered carbon and manganese oxide prevents hydrogen from forming on the carbon rod, which would stop the cell from working normally. For the negative electrode, Zinc is used, which serves, as a case for the cell. Electrons flow from the negative terminal through a wire in the device the battery is powering into the positive terminal (learning center). The most common cell is the dry cell and different types have different types of electrolytes. The dry cell works like the cell invented by the French engineer Georges Leclanceh in 1865. His cell had a liquid electrolyte, but in the modern version the electrolyte is ammonium chloride paste(DK Science 150). Ordinary dry cells are used in most