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Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra 3 N 2).
radium-215m2: 1.39 bismuth-211m: 1.4 uranium-222: 1.4 radium-217: 1.63 neptunium-223: 2.15 radium-210m: 2.24 radon-215: 2.30 bismuth-217m: 2.70 polonium-211m3: 2.8 radon-209m2: 3.0 bismuth-202m1: 3.04 polonium-213: 3.65 lead-198m1: 4.19 protactinium-221: 4.9 astatine-210m2: 5.66 nobelium-250: 5.7 lead-212m: 6.0 lead-214m: 6.2 bismuth-187m2: 7 ...
The only stable nuclides having an odd number of protons and an odd number of neutrons are hydrogen-2, lithium-6 ... radium (88 Ra) discovered in 1898, curium ...
Following its discovery by Marie and Pierre Curie in 1898, radium (principally 226 Ra) has had a number of uses. In the early 20th century, when the hazards of radiation were not well-known, radium was commonly used in consumer items such as toothpaste and hair creams.
The number of protons (Z column) and number of neutrons (N column). energy column The column labeled "energy" denotes the energy equivalent of the mass of a neutron minus the mass per nucleon of this nuclide (so all nuclides get a positive value) in MeV, formally: m n − m nuclide / A, where A = Z + N is the mass number. Note that this means ...
Radium (88 Ra) has no stable or nearly stable isotopes, and thus a standard atomic weight cannot be given. The longest lived, and most common, isotope of radium is 226 Ra with a half-life of 1600 years. 226 Ra occurs in the decay chain of 238 U (often referred to as the radium series). Radium has 34 known isotopes from 201 Ra to 234 Ra.
Radium-224 is a radioactive atom that is utilized as a source of alpha radiation in a cancer treatment device called DaRT (diffusing alpha emitters radiation therapy). Each radium-224 atom undergoes a decay process producing 6 daughter atoms. During this process, 4 alpha particles are emitted.
Although radium-223 is naturally formed in trace amounts by the decay of uranium-235, it is generally made artificially, [9] by exposing natural radium-226 to neutrons to produce radium-227, which decays with a 42-minute half-life to actinium-227. Actinium-227 (half-life 21.8 years) in turn decays via thorium-227 (half-life 18.7 days) to radium ...