Main-group element Main-group element In chemistry and atomic physics, the main group is the group of elements whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements. The main group includes the elements (except hydrogen, which is sometimes not included) in groups 1 and 2 (s-block), and groups 13 to 18 (p-block). The s-block elements are primarily characterised by one main oxidation state, and the p-block elements, when they have multiple oxidation states, often have common oxidation states separated by two units. Main-group elements (with some of the
Power Processing Element Power Processing Element The Power Processing Unit (PPU) is a 64-bit dual threaded in-order Power Architecture microprocessor core designed by IBM for use primarily in the game consoles PlayStation 3 and Xbox 360, but has also found applications in high performance computing in supercomputers such as the record setting IBM Roadrunner. In most instances the PPU is joined by a 512 KB L2 cache to form what is called the Power Processing Element (PPE). The PPU is used as a main CPU core in three different processor designs: The PPU is an In-Order processor, but it has some unique traits