Which of the elements is the least stable?

sequoianoir

Of the first 101 element of the periodic table: FRANCIUM Discovered in 1939 by Mlle. Marguerite Perey of the Curie Institute, Paris. Francium, the heaviest known member of the alkali metals series, occurs as a result of analpha disintegration of actinium. It can also be made by artificially bombarding thorium with protons. While it occurs naturally in uranium minerals, there is probably less than an ounce of francium at any time in the total crust of the earth. It has the highest equivalent weight of any element, and is the most unstable of the first 101 elements ofthe periodic system. Thirty-three isotopes of francium are recognized. The longest lived 223Fr (Ac, K), a daughter of 227Ac, has a half-life of 22 min. This is the only isotope of francium occurring in nature. Because all known isotopes of francium are highly unstable, knowledge of the chemical properties of this element comes from radiochemical techniques. No weighable quantity of the element has been prepared or isolated. The chemical properties of francium most resemble caesium. Oct 23 03, 11:34 AM