Seaborgium element isotopes

Most of the chemical and physical properties of imniloctium (hassium) are unknown. What is known is that its most stable isotope (hassium-108) has the atomic weight (mass) of about 277. Hs-277 has a half-life of about 12 minutes, after which it decays into the isotope seaborgium-273 through either alpha decay or spontaneous fission. Hassium is the last element located at the bottom of group 8, and like element 107, it is produced by a cold fusion process that in hassium s case is accomplished by slamming iron (Fe-58) into particles of the isotope of lead (Pb-209), along with several neutrons, as follows ... 

As these superheavy elements get heavier, they become less stable the nuclei sit around for progressively shorter times before undergoing radioactive decay. Plutonium-239 has a half-life of 24,000 years, which means that it takes this long for half the atoms in a sample of Pu to decay. Califomium-249 (element 98) has a half-life of350 years mendelevium-258 (lOl), fifty-one days seaborgium-266 (106) twenty-one seconds. Isotope 272 of element 111 has a fleeting existence with a half-life of 1.5 milliseconds, and that of isotope 277 of element 112, made in 1996, is less than a third of a millisecond. This is one reason why it becomes increasingly hard to make and see these superheavy elements. ... 

Based on theoretical calculations some researchers believe that not all transuranium elements will be so unstable. Already, different isotopes of element 106, seaborgium (Sg) have been made that are stable for up 33 times longer than the original isotope discovered in 1974 (even at 33 times longer lifetime it only is stable for a maximum of thirty seconds). It is theorized that some isotopes of the yet to be made transuranium elements should be stable for very long periods of time, allowing them to be studied chemically. Many exciting... 

Element 106, named seaborgium to honor Glen Seaborg, was created in 1974 by the Flerov Laboratory of Nuclear Reactions in Dubna, in the Soviet Union, and at the Lawrence Berkeley and Livermore Laboratories, in the United States. Seaborgium isotopes are created using a cyclotron and can exist from about 0.9 seconds up to about 20 seconds before they decay into other elements. This is enough time to determine the properties of seaborgium and to confirm that it qualifies as an element. 

Seaborgium-263 (Sg Z = 106) was the first isotope of this element synthesized. It was made, together with four neutrons, by bombarding californium-249 with oxygen-18. It then decayed by three a emissions. Write balanced equations for the synthesis and three decay steps of " Sg. 

The first atoms of seaborgium (Sg) were identified in i974. The longest-lived isotope of Sg has a mass number of 266. (a) How many protons, electrons, and neutrons are in an Sg atom (b) Atoms of Sg are very unstable, and it is therefore difficult to study this element s properties. Based on the position of Sg in the periodic table, what element should it most closely resemble in its chemical properties ... 

Write nuclear equations to represent the formation of a hypothetical isotope of element 118 with a mass number of 293 by the bombardment of lead-208 by krypton-86 nuclei, followed by a chain of a-particle emissions to the element seaborgium. 

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