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A synthetic, radioactive element, curium is a hard, dense metal with a silvery-white appearance and physical and chemical properties resembling gadolinium. Its melting point of 1344 °C is significantly higher than that of the previous elements neptunium (637 °C), plutonium (639 °C) and americium (1176 °C).
Curium (96 Cm) is an artificial element with an atomic number of 96. Because it is an artificial element, a standard atomic weight cannot be given, and it has no stable isotopes. The first isotope synthesized was 242 Cm in 1944, which has 146 neutrons. There are 19 known radioisotopes ranging from 233 Cm to 251 Cm. There are also ten known ...
The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...
The existence of isotopes was first suggested in 1913 by the radiochemist Frederick Soddy, based on studies of radioactive decay chains that indicated about 40 different species referred to as radioelements (i.e. radioactive elements) between uranium and lead, although the periodic table only allowed for 11 elements between lead and uranium ...
Pages in category "Isotopes of curium" The following 22 pages are in this category, out of 22 total. This list may not reflect recent changes. ...
Rubidium is the first alkali metal in the group to have a density higher than water. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85 Rb, and 28% is slightly radioactive 87 Rb, with a half-life of 48.8 billion years – more than three times as long as the estimated age of the universe.
Cerium is a chemical element; it has symbol Ce and atomic number 58. It is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the oxidation state of +3 characteristic of the series, it also has a stable +4 state that does not oxidize water.
Exceptions to the principle also occur later in the periodic table for elements such as copper, niobium and molybdenum. [ 14 ] Chromium is the first element in the 3d series where the 3d electrons start to sink into the core; they thus contribute less to metallic bonding , and hence the melting and boiling points and the enthalpy of atomisation ...