Mendelevium

Element 101 on the periodic table, symbol Md, group 3, period 7.

Mendelevium is a synthetic element with chemical symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranic element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements. It is the antepenultimate actinide and the ninth transuranic element.

Properties

Atomic Number: 101
Atomic Mass: 258.0000 u
Group: 3
Period: 7
Block: f-block
Category: Actinide
State at 25 °C: Solid
Melting Point: 1,100 K · 826.9 °C
Boiling Point: Not measured
Density: Not measured
Atomic Radius: Not measured
Electronegativity: 1.3
Oxidation States: +2, +3
Abundance in Crust: Vanishingly rare
Discovered: 1955
Discovered By: Lawrence Berkeley National Laboratory

Electron Configuration

[Rn] 5f13 7s2

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f13

Ionisation Energies (kJ/mol)

1. 635

Elements near Mendelevium

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.