Lawrencium (Lr)

Lawrencium is a synthetic chemical element with symbol Lr and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements.

Atomic Number

103

Atomic Mass

266 u

Category

actinide

Phase

solid

Density

16 g/cm³

Electron Shells

2, 8, 18, 32, 32, 8, 3

Atomic Structure

Protons: 103 • Electrons: 103 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 7p¹

Discovery

1961 • Albert Ghiorso, Torbjorn Sikkeland, Almon Larsh, Robert M. Latimer