67
Ho
Holmium
164.930332
Holmium
LANTHANIDE
Bohr Model: Electrons arranged in energy shells around the nucleus.
Holmium is a chemical element with symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve.
Quick Facts
Atomic Number 67
Period 6
Group 13
Phase Solid
Appearance silvery white
About Lanthanides
Lanthanides are shiny metallic elements with atomic numbers 57–71. They are often called 'rare-earth elements' and are used in magnets and lasers.
History
Discovered By Marc Delafontaine
Named By Unknown
Physical Properties
Atomic Mass 164.930332
Density 8.79 g/L
Molar Heat 27.15 J/(mol·K)
Phase Transition (Melting & Boiling Points)
Holmium melts at 1734 K and boils at 2873 K.
Atomic Properties
Electron Config [Xe] 4f11 6s2
Electronegativity 1.23
Electron Affinity 32.61 kJ/mol
Ionization Energy 581 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.