Element: Bismuth

General data

Element name	Bismuth
Chemical symbol	Bi
Atomic number Z	83
Year discovered	1753
Standard state (25°C)	Solid
Category	Post-transition metal
Block	p
Atomic mass	208.98
CPK color	#9E4FB5

Physical properties

Melting point	544.55 K (271.40 °C)
Boiling point	1837 K (1564 °C)
Density	9.807 g/cm³

Energy properties

First ionization energy	7.289 eV
Electron affinity	0.946 eV

Atomic structure

Protons	83 (Atomic number)
Neutrons (Bi-209, most abundant isotope)	126
Electrons	83
Electron configuration	[Xe] 6s² 4f¹⁴ 5d¹⁰ 6p³
Oxidation states	+5, +3
Electronegativity (Pauling)	2.02
Atomic radius (van der Waals)	207 pm

Ionization energies - NIST ASD (83 states)

State	Charge	Ioniz. energy (eV)	Type
Bi I	0+	7.285516 ± 0.000006	measured
Bi II	1+	16.703 ± 0.004	measured
Bi III	2+	25.57075 ± 0.00017	measured
Bi IV	3+	45.37 ± 0.06	measured
Bi V	4+	54.856 ± 0.025	measured
Bi VI	5+	88.4 ± 0.7	semi-empirical
Bi VII	6+	103 ± 2	calculated
Bi VIII	7+	122 ± 2.1	calculated
Bi IX	8+	143 ± 2.2	calculated
Bi X	9+	161.1 ± 2.2	calculated
Bi XI	10+	183 ± 2.4	calculated
Bi XII	11+	208 ± 2.5	calculated
Bi XIII	12+	229 ± 3	calculated
Bi XIV	13+	252 ± 3	calculated
Bi XV	14+	272.6 ± 2.5	semi-empirical
Bi XVI	15+	370.2 ± 1.6	semi-empirical
Bi XVII	16+	409 ± 20	calculated
Bi XVIII	17+	436 ± 22	calculated
Bi XIX	18+	464 ± 23	calculated
Bi XX	19+	520 ± 30	calculated
Bi XXI	20+	550 ± 30	calculated
Bi XXII	21+	620 ± 30	calculated
Bi XXIII	22+	660 ± 30	calculated
Bi XXIV	23+	690 ± 30	calculated
Bi XXV	24+	750 ± 40	calculated
Bi XXVI	25+	810 ± 40	calculated
Bi XXVII	26+	870 ± 50	calculated
Bi XXVIII	27+	930 ± 50	calculated
Bi XXIX	28+	990 ± 50	calculated
Bi XXX	29+	1060 ± 50	calculated
Bi XXXI	30+	1120 ± 60	calculated
Bi XXXII	31+	1180 ± 60	calculated
Bi XXXIII	32+	1250 ± 60	calculated
Bi XXXIV	33+	1310 ± 70	calculated
Bi XXXV	34+	1380 ± 70	calculated
Bi XXXVI	35+	1440 ± 70	calculated
Bi XXXVII	36+	1500 ± 70	calculated
Bi XXXVIII	37+	1784 ± 4	calculated
Bi XXXIX	38+	1840 ± 4	calculated
Bi XL	39+	1902 ± 4	calculated
Bi XLI	40+	1967 ± 4	calculated
Bi XLII	41+	2029 ± 4	calculated
Bi XLIII	42+	2090 ± 4	calculated
Bi XLIV	43+	2190 ± 4	calculated
Bi XLV	44+	2253 ± 4	calculated
Bi XLVI	45+	2321 ± 4	calculated
Bi XLVII	46+	2385 ± 4	calculated
Bi XLVIII	47+	2641 ± 4	calculated
Bi XLIX	48+	2703 ± 4	calculated
Bi L	49+	2771 ± 4	calculated
Bi LI	50+	2835 ± 4	calculated
Bi LII	51+	3078 ± 4	calculated
Bi LIII	52+	3151 ± 4	calculated
Bi LIV	53+	3329 ± 5	calculated
Bi LV	54+	3401.8 ± 2.4	semi-empirical
Bi LVI	55+	5599 ± 5	calculated
Bi LVII	56+	5740 ± 5	calculated
Bi LVIII	57+	5892 ± 6	calculated
Bi LIX	58+	6054 ± 6	calculated
Bi LX	59+	6208 ± 7	calculated
Bi LXI	60+	6358 ± 10	calculated
Bi LXII	61+	6648 ± 12	calculated
Bi LXIII	62+	6804 ± 15	calculated
Bi LXIV	63+	6977 ± 19	calculated
Bi LXV	64+	7137 ± 24	calculated
Bi LXVI	65+	7580 ± 30	calculated
Bi LXVII	66+	7720 ± 40	calculated
Bi LXVIII	67+	7870 ± 40	calculated
Bi LXIX	68+	8010 ± 50	calculated
Bi LXX	69+	8780 ± 50	calculated
Bi LXXI	70+	8950 ± 60	calculated
Bi LXXII	71+	9270 ± 60	calculated
Bi LXXIII	72+	9430 ± 70	calculated
Bi LXXIV	73+	20130 ± 90	calculated
Bi LXXV	74+	20500 ± 90	calculated
Bi LXXVI	75+	20920 ± 100	calculated
Bi LXXVII	76+	21300 ± 110	calculated
Bi LXXVIII	77+	24150 ± 120	calculated
Bi LXXIX	78+	24640 ± 120	calculated
Bi LXXX	79+	25260 ± 140	calculated
Bi LXXXI	80+	25656.9 ± 0.4	calculated
Bi LXXXII	81+	102251.8 ± 0.4	calculated
Bi LXXXIII	82+	104133.4 ± 0.3	calculated

Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.

Photos

Photo of the element: Bismuth (Bi) — © images-of-elements.com (CC BY 3.0)

Isotopes (41)

A	N	Half-life	Decay
Bi-184	101	13 ms	α
Bi-185	102	2.8 μs	p
Bi-186	103	14.8 ms	α
Bi-187	104	37 ms	α
Bi-188	105	60 ms	α
Bi-189	106	685 ms	α
Bi-190	107	6.3 s	α
Bi-191	108	12.4 s	α
Bi-192	109	34.6 s	EC/β⁺
Bi-193	110	63.0 s	EC/β⁺
Bi-194	111	100 s	EC/β⁺
Bi-195	112	183 s	EC/β⁺
Bi-196	113	5.13 min	EC/β⁺
Bi-197	114	9.3 min	EC/β⁺
Bi-198	115	10.3 min	EC/β⁺
Bi-199	116	27 min	EC/β⁺
Bi-200	117	36.4 min	EC/β⁺
Bi-201	118	111 min	EC/β⁺
Bi-202	119	1.71 h	EC/β⁺
Bi-203	120	11.76 h	EC/β⁺
Bi-204	121	11.28 h	EC/β⁺
Bi-205	122	14.91 d	EC/β⁺
Bi-206	123	6.243 d	EC/β⁺
Bi-207	124	31.22 a	EC/β⁺
Bi-208	125	3.68×10⁵ a	EC/β⁺
Bi-209	126	2.01×10¹⁹ a	α
Bi-210	127	5.012 d	β⁻
Bi-211	128	2.14 min	α
Bi-212	129	60.55 min	α
Bi-213	130	45.61 min	β⁻
Bi-214	131	19.71 min	β⁻
Bi-215	132	7.6 min	β⁻
Bi-216	133	2.25 min	β⁻
Bi-217	134	98.5 s	β⁻
Bi-218	135	33 s	β⁻
Bi-219	136	9 s	β⁻
Bi-220	137	10 s	β⁻
Bi-221	138	unknown	β⁻
Bi-222	139	unknown	β⁻
Bi-223	140	unknown	β⁻
Bi-224	141	unknown	β⁻

Data sources

PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0

More about the data sources