Mendelevium

Mendelevium (Md) is a synthetic actinide chemical element of atomic number 101 and atomic mass ~258 u. This sheet describes its fundamental properties, periodic-table position and physical characteristics.

Identity

• Name: Mendelevium
• Symbol: Md
• Atomic number: 101
• Standard atomic mass: ~ 258 u

Position in the periodic table

• Block: f (Actinides)
• Period: 7
• Category: Synthetic actinide element

Physico-chemical properties

• Standard state: Solid (predicted)
• Melting point: Estimated ~ 827 °C (experimental data limited)
• Density: Predicted ~ 10.3 g·cm⁻³ (no bulk sample)
• Electron configuration: [Rn] 5f¹³ 7s² (some sources list [Rn] 5f¹² 6d¹ 7s²)

Scientific description

Mendelevium is a synthetic chemical element with symbol Md and atomic number 101. It belongs to the actinide series and lies in period 7 of the periodic table. The element does not occur naturally; its isotopes are radioactive and produced only in trace amounts. The most stable known isotope is ^258Md with a half-life of about 51.5 days. Mendelevium currently has no commercial applications.