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103 Lr Lawrencium 266

Lawrencium

ACTINIDE
Bohr Model: Electrons arranged in energy shells around the nucleus.

Lawrencium is a synthetic chemical element with chemical symbol Lr (formerly Lw) 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. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series.

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Quick Facts

Atomic Number 103
Period 7
Group 17
Phase Solid
Appearance Unknown
About Actinides

Actinides are the 15 metallic elements with atomic numbers 89–103. All actinides are radioactive.

History

Discovered By Lawrence Berkeley National Laboratory
Named By Unknown

Physical Properties

Atomic Mass 266
Density N/A g/L
Molar Heat N/A J/(mol·K)
Phase Transition (Melting & Boiling Points)

Lawrencium melts at 1900 K. The boiling point is currently unknown.

Atomic Properties

Electron Config [Rn] 5f14 7s2 7p1
Electronegativity 1.3
Electron Affinity -30.04 kJ/mol
Ionization Energy 470 kJ/mol
Orbital Filling Diagram
This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule. Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down. Electrons fill lower energy levels first and occupy orbitals singly before pairing.

Photograph

Image of Lawrencium Source: Wikipedia

External Resources

Wikipedia PubChem Royal Society of Chemistry Periodic Videos (YouTube)

Study Guide

Atomic Number

The number of protons in the nucleus, which defines the element.

Atomic Mass

The average mass of an atom, including protons and neutrons.

Electronegativity

A measure of how strongly an atom attracts electrons in a bond.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Config

The arrangement of electrons in the atom's energy shells.