د ويکيپېډيا، وړیا پوهنغونډ له خوا
Berkelium, 97 Bk Pronunciation / b ər ˈ k iː l i . əm / ; less commonly: / ˈ b ɜr k l i . əm / bər-KEE -lee-əm ; BERK -lee-əmAppearance silvery اټومي شمیره (Z ) 97 گروپ , پیریود group n/a , period 7 بلاک f-block Element category actinide Mass number 247 (most stable isotope) Electron configuration [Rn ] 5f9 7s2 Electrons per shell
2, 8, 18, 32, 27, 8, 2 حالت (at STP ) جامد دويلې کيدو ټکى beta: 1259 K (986 °C, 1807 °F) يشنا ټکی beta: 2900 K (2627 °C, 4760 °F) Density near r.t. alpha: 14.78 g/cm3 beta: 13.25 g/cm3 Heat of fusion 7.92 kJ/mol (calculated) Oxidation states 2, 3 , 4 Electronegativity Pauling scale: 1.3 Ionization energies Atomic radius empirical: 170 pm Crystal structure double hexagonal close-packed (dhcp)Double hexagonal close packed crystal structure for berkelium د تودوخې تېرېدنه 10 W/(m·K) Magnetic ordering paramagnetic CAS Number 7440-40-6 Naming after Berkeley, California , where it was discovered Discovery Lawrence Berkeley National Laboratory (1949)
| references | in Wikidata
Element navigation
سرچينې
د سرچينو همدا لړليک په ليکنه کې نه ښکاري.
↑ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics . 71 (2): 299. doi :10.1016/0029-5582(65)90719-4 .