92
U
Uranium
238.028913
Uranium
ACTINIDE
Bohr Model: Electrons arranged in energy shells around the nucleus.
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-white metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons.
Quick Facts
Atomic Number 92
Period 7
Group 6
Phase Solid
Appearance Unknown
About Actinides
Actinides are the 15 metallic elements with atomic numbers 89–103. All actinides are radioactive.
History
Discovered By Martin Heinrich Klaproth
Named By Unknown
Physical Properties
Atomic Mass 238.028913
Density 19.1 g/L
Molar Heat 27.665 J/(mol·K)
Phase Transition (Melting & Boiling Points)
Uranium melts at 1405.3 K and boils at 4404 K.
Atomic Properties
Electron Config [Rn] 5f3 6d1 7s2
Electronegativity 1.38
Electron Affinity 50.94 kJ/mol
Ionization Energy 597.6 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
External Resources
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.