101 Mendelevium H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm[Md]No Lr +--------------------+ |101 __ __ _ | | | \/ | __| | | | | |\/| |/ _` | | | | | | | (_| | | | |_| |_|\__,_| | | | | Mendelevium | | 258.09843 u | +--------------------+ Electron Configuration: [Rn]7s2 5f13 Electronegativity: 1.3 Atomic Radius: Ionization Energy: 6.58 eV Electron Affinity: Oxidation States: +3, +2 Standard State: Solid Melting Point: 1100 K Boiling Point: Density: Family: Actinide Year Discovered: 1955 Number of Neutrons: 157 Number of Protons: 101 Number of Electrons: 101 Number of Valence: Valency: Group: Period: 7 Shell: f-shell Specific Heat: Radioactive: 1 Occurrence: Synthetic Source: Human-made