Period 6 element period 6 other metals are incredibly toxic, such as thallium. Period 6 contains the last stable element, lead. All subsequent elements in the periodic table are radioactive. After bismuth, which has a half-life or more than 10 years, polonium, astatine, and radon are some of the shortest-lived and rarest elements known; less than a gram of astatine is estimated to exist on earth at any given time. Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes
C-element and the latch outputs its previous state. There are also versions of semistatic C-element built on devices with negative differential resistance (NDR). It should be noted however, that NDR is usually defined for small signal. So, it is difficult to expect that such a C-element will operate in full range of voltages or currents. Since the majority gate is a particular case of threshold gate, any of known realizations of threshold gate can in principle be used for building a C-element. In the multiple-valued case, however, connecting the output of majority gate to one or several inputs may have no