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
Hard and soft C or an alveolo-palatal , and occurs before not only , and , but also , , and . Another similar system with hard and soft is found in Faroese with the hard being and the soft being , and Turkish where the soft is . The Vietnamese alphabet does not have a hard or a soft per se. However, since it was inherited from European languages, the letter never occurs in "soft positions", i.e. before , and where is used instead, while never occurs elsewhere except in the digraph and a few loanwords. Hồ Chí Minh had proposed a simplified