What Is Bismuth?
With atomic number 83 and chemical symbol Bi, Bismuth sits among the post-transition metals just right of the main transition block.
A heavy, brittle metal with a distinctive iridescent oxide surface.
As a post-transition metal in Period 6 and Group 15 (Nitrogen Group / Pnictogens), bismuth's placement on the table reflects its electron configuration of [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³, which governs its bonding behavior and the type of compounds it typically forms.
Position on the Periodic Table
Bismuth is located in Period 6, an unusually long row that includes the entire lanthanide series.
Within that row, bismuth sits in Group 15 (Nitrogen Group / Pnictogens), alongside elements that share a similar number of valence electrons and, by extension, similar chemical behavior.
This position is not arbitrary — the periodic table was deliberately organized so that an element's row and column reveal its expected reactivity, bonding pattern, and physical state at a glance.
Physical & Chemical Properties
Bismuth has an atomic mass of 208.980 u and a density of 9.78 g/cm³. Its melting point is 271.4°C and its boiling point is 1564°C.
Bismuth is generally softer and lower-melting than the transition metals positioned to its left on the periodic table.
Electron Configuration Explained
Bismuth's electron configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³, describing how its electrons are distributed across shells and subshells around the nucleus.
Reading the configuration in order shows electrons filling shells of increasing energy, following the standard Aufbau principle that explains how atomic structure builds up across the periodic table.
The outermost (valence) electrons shown in this configuration are what ultimately determine bismuth's chemical reactivity and the type of bonds it forms with other elements.
History & Discovery
Bismuth was formally discovered in 1753, C.F. Geoffroy, identified through the careful isolation and analytical techniques typical of that era's chemical research.
Many elements from this period were anticipated by Dmitri Mendeleev's periodic table, which successfully predicted gaps corresponding to undiscovered elements well before laboratory instruments existed to confirm them directly.
What Is Bismuth Used For?
Bismuth's specific properties make it useful in several applications, including:
- Pepto-Bismol (medicine)
- Low-melting alloys
- Cosmetics
- Fire sprinkler systems
- Nuclear shielding
These uses reflect bismuth's underlying classification as a post-transition metal, since the same properties that define its category in chemistry also determine where it becomes practically useful.
Fun Facts About Bismuth
- Bismuth crystals grown from molten bismuth form beautiful rainbow-colored hopper crystals.
- Bismuth is element number 83 on the periodic table, in Period 6 and Group 15.
- Its standard atomic mass is 208.980 u, calculated from the natural abundance of its isotopes.
Frequently Asked Questions
What is Bismuth's atomic number?
Bismuth has atomic number 83.
What is Bismuth's chemical symbol?
Bismuth's symbol is Bi.
What group and period is Bismuth in?
Bismuth is in Period 6, Group 15 (Nitrogen Group / Pnictogens).
What is Bismuth's atomic mass?
Bismuth's standard atomic mass is 208.980 u.