Atomic Number
65
Element 65
Terbium (Tb)
Terbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife.
Atomic Mass
158.93 u
Category
Lanthanide
Period
6
Group
Lanthanide series
Phase
solid
Density
8.23 g/cm3
Electron Shells
2, 8, 18, 27, 8, 2
Atomic Structure
Protons: 65. Electrons: 65. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁹
Why Terbium Matters
Terbium helps connect atomic number 65, lanthanide behavior, period 6 trends, and electron shell structure. Its solid phase, atomic mass of 158.93 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁹ make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Terbium was discovered 1843 by Carl Gustaf Mosander. Terbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife.
Safety and Handling Context
Terbium is presented here for learning and comparison. Pure elements and laboratory compounds can have hazards that depend on dose, form, and setting.
Related Elements
Frequently Asked Questions
- What is the atomic number of Terbium?
- Terbium has atomic number 65, which means a neutral atom has 65 protons and 65 electrons.
- What is the chemical symbol for Terbium?
- The chemical symbol for Terbium is Tb.
- What category is Terbium in?
- Terbium is classified as a lanthanide and sits in period 6 of the periodic table.
Explore Terbium in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Terbium to neighboring elements without losing your place.