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Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, 267 Rf, has a half-life of about 48 minutes.
The last element of the group, rutherfordium, does not occur naturally and had to be made by synthesis. The first reported detection was by a team at the Joint Institute for Nuclear Research (JINR), which in 1964 claimed to have produced the new element by bombarding a plutonium -242 target with neon -22 ions, although this was later put into ...
[21] [52] The ruthenium plate is applied to the electrical contact and electrode base metal by electroplating [53] or sputtering. [54] Ruthenium dioxide with lead and bismuth ruthenates are used in thick-film chip resistors. [55] [56] [57] These two electronic applications account for 50% of the ruthenium consumption. [24]
A metalloid is an element that possesses a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals, and which is therefore hard to classify as either a metal or a nonmetal. This is a generic definition that draws on metalloid attributes consistently cited in the literature.
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.
Praseodymium is an electropositive element and reacts slowly with cold water and quite quickly with hot water to form praseodymium(III) hydroxide: [17] 2 Pr (s) + 6 H 2 O (l) → 2 Pr(OH) 3 (aq) + 3 H 2 (g) Praseodymium metal reacts with all the stable halogens to form trihalides: [17] 2 Pr (s) + 3 F 2 (g) → 2 PrF 3 (s) [green]
Nevertheless, the Russian team conducted further studies on the thermodynamics of cocrystallizing mendelevium with alkali metal chlorides, and concluded that mendelevium(I) had formed and could form mixed crystals with divalent elements, thus cocrystallizing with them. The status of the +1 oxidation state is still tentative.
This stability is very important for superheavy elements: with no stabilization, half-lives would be expected by exponential extrapolation to be nanoseconds at darmstadtium (element 110), because the ever-increasing electrostatic repulsion between protons overcomes the limited-range strong nuclear force that holds nuclei together. The next ...