Mendelevium
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.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
86 is the [Rn] core total across six shells.
At a glance
- Atomic number
- 101
- Atomic mass
- 258 u
- Phase
- Solid
- Density
- Unavailable
- Melting point
- 1,100 K
- Boiling point
- Unavailable
- First ionization energy
- 635 kJ/mol
- Electronegativity
- 1.3
- Electron affinity
- 93.91 kJ/mol
- Molar heat capacity
- Unavailable
- Period
- 7
- Appearance
- Unavailable
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.