Selenium

Ngoc Tran

Element Name : Selenium Atomic Number : 34 Atomic Mass : 78.96 Protons : 34 Electrons : 34 Neutrons : 45 Selenium Electron Configuration : [Ar] 3d10 4s2 4p4

In chemical activity and physical properties it resembles sulfur and tellurium.

Jöns Jacob Berzelius discovered Selenium in 1817. "He reported that tellurium was present in sulphuric acid from a Swedish factory, but in the following year decided that the impurity was not tellurium but another closely related element that he subsequently identified as selenium".

Selenium is found in alfalfa, burdock root, catnip, fennel seed, ginseng, raspberry leaf, radish, horseradish, onion, chives, medicinal mushrooms (reishi, shiitake), and yarroPr

Isotopes of Selenium
symbol ||~ Z([|p]) ||~ N([|n]) ||~ isotopic mass (u) ||~ half-life ||~ nuclear spin ||~ representative isotopic composition (mole frProxy-Connection: keep-alive Cache-Control: max-age=0 tion) ||~ range of natural variation (mole fraction) ||
 * ~ nuclide
 * 65Se ||> 34 ||> 31 || 64.96466(64)# || <50 ms || 3/2-# ||  ||   ||
 * 66Se ||> 34 ||> 32 || 65.95521(32)# || 33(12) ms || 0+ ||  ||   ||
 * 67Se ||> 34 ||> 33 || 66.95009(21)# || 133(11) ms || 5/2-# ||  ||   ||
 * 68Se ||> 34 ||> 34 || 67.94180(4) || 35.5(7) s || 0+ ||  ||   ||
 * 69Se ||> 34 ||> 35 || 68.93956(4) || 27.4(2) s || (1/2-) ||  ||   ||
 * 69m1Se |||||| 39.4(1) keV || 2.0(2) µs || 5/2- ||  ||   ||
 * 69m2Se |||||| 573.9(10) keV || 955(16) ns || 9/2+ ||  ||   ||
 * 70Se ||> 34 ||> 36 || 69.93339(7) || 41.1(3) min || 0+ ||  ||   ||
 * 71Se ||> 34 ||> 37 || 70.93224(3) || 4.74(5) min || 5/2- ||  ||   ||
 * 71m1Se |||||| 48.79(5) keV || 5.6(7) µs || 1/2- to 9/2- ||  ||   ||
 * 71m2Se |||||| 260.48(10) keV || 19.0(5) µs || (9/2)+ ||  ||   ||
 * [|72Se] ||> 34 ||> 38 || 71.927112(13) || 8.40(8) d || 0+ ||  ||   ||
 * 73Se ||> 34 ||> 39 || 72.926765(11) || 7.15(8) h || 9/2+ ||  ||   ||
 * 73mSe |||||| 25.71(4) keV || 39.8(13) min || 3/2- ||  ||   ||
 * 74Se ||> 34 ||> 40 || 73.9224764(18) || STABLE || 0+ || 0.0089(4) ||  ||
 * 75Se ||> 34 ||> 41 || 74.9225234(18) || 119.779(4) d || 5/2+ ||  ||   ||
 * [|76Se] ||> 34 ||> 42 || 75.9192136(18) || STABLE || 0+ || 0.0937(29) ||  ||
 * 77Se ||> 34 ||> 43 || 76.9199140(18) || STABLE || 1/2- || 0.0763(16) ||  ||
 * 77mSe |||||| 161.9223(7) keV || 17.36(5) s || 7/2+ ||  ||   ||
 * [|78Se] ||> 34 ||> 44 || 77.9173091(18) || STABLE || 0+ || 0.2377(28) ||  ||
 * [|79Se] ||> 34 ||> 45 || 78.9184991(18) || 2.95(38)E+5 a || 7/2+ ||  ||   ||
 * 79mSe |||||| 95.77(3) keV || 3.92(1) min || 1/2- ||  ||   ||
 * 80Se ||> 34 ||> 46 || 79.9165213(21) || STABLE (TDB) || 0+ || 0.4961(41) ||  ||
 * 81Se ||> 34 ||> 47 || 80.9179925(22) || 18.45(12) min || 1/2- ||  ||   ||
 * 81mSe |||||| 102.99(6) keV || 57.28(2) min || 7/2+ ||  ||   ||
 * [|82Se] ||> 34 ||> 48 || 81.9166994(22) || 97(5)E+18 a || 0+ || 0.0873(22) ||  ||
 * 83Se ||> 34 ||> 49 || 82.919118(4) || 22.3(3) min || 9/2+ ||  ||   ||
 * 83mSe |||||| 228.50(20) keV || 70.1(4) s || 1/2- ||  ||   ||
 * 84Se ||> 34 ||> 50 || 83.918462(16) || 3.1(1) min || 0+ ||  ||   ||
 * 85Se ||> 34 ||> 51 || 84.92225(3) || 31.7(9) s || (5/2+)# ||  ||   ||
 * 86Se ||> 34 ||> 52 || 85.924272(17) || 15.3(9) s || 0+ ||  ||   ||
 * 87Se ||> 34 ||> 53 || 86.92852(4) || 5.50(12) s || (5/2+)# ||  ||   ||
 * 88Se ||> 34 ||> 54 || 87.93142(5) || 1.53(6) s || 0+ ||  ||   ||
 * 89Se ||> 34 ||> 55 || 88.93645(32)# || 0.41(4) s || (5/2+)# ||  ||   ||
 * 90Se ||> 34 ||> 56 || 89.93996(43)# || 300# ms [>300 ns] || 0+ ||  ||   ||
 * 91Se ||> 34 ||> 57 || 90.94596(54)# || 270(50) ms || 1/2+# ||  ||   ||
 * 92Se ||> 34 ||> 58 || 91.94992(64)# || 100# ms [>300 ns] || 0+ ||  ||   ||
 * 93Se ||> 34 ||> 59 || 92.95629(86)# || 50# ms [>300 ns] || 1/2+# ||  ||   ||
 * 94Se ||> 34 ||> 60 || 93.96049(86)# || 20# ms [>300 ns] || 0+ ||  ||   ||
 * 94Se ||> 34 ||> 60 || 93.96049(86)# || 20# ms [>300 ns] || 0+ ||  ||   ||

Sources: www.**webelements**.com/ www.wikipedia.org/
 * education**.**jlab**.org/