105 Db (Dubnium)
Mass number – 268
Atomic number (Z) – 105
Atomic weight – 262 g/mol
Electrons – 105
Protons – 105
Neutrons – 163
Group 5
Period – 7
Block – d
Element category – Transition metal
Electrons per shell – K2, L8, M18, N32, O32, P11, Q2
Electron configuration – 1s22s22p63s23p63d104s24p64d105s25p64f145d106s26p65f146d37s2
Phase – Solid
Density – 29.3 g/cm3
Half Life(s) – 20000
Lifetime(s) – 30000
Appearance – Highly Radioactive metal
Oxidation states – 5, 4, 3
Ionization energies – 1st: 656.1 kJ/mol, 2nd: 1546.7 kJ/mol, 3rd:2378.4 kJ/mol
Atomic radius – 139 pm
Covalent radius – 149 pm
Crystal structure – Body-centered cubic
CAS Number – 53850-35-4
Naming – After Dubna, Moscow Oblast, Russia (Site of the JINR)
Discovery – Independently by the University of California and the (JINR)Joint Institute for Nuclear Research (1970)
Isotopes – 262Db 263Db 266Db 267Db 268Db 270Db
Uses – At present, it is only used in research.
Natural abundance – It is a transuranium element created by bombarding californium-249 with nitrogen-15 nuclei
#Dubnium