Element: Mercury

General data

Element name	Mercury
Chemical symbol	Hg
Atomic number Z	80
Year discovered	known since antiquity
Standard state (25°C)	Liquid
Category	Transition metal
Block	d
Atomic mass	200.59
CPK color	#B8B8D0

Physical properties

Melting point	234.32 K (-38.83 °C)
Boiling point	629.88 K (356.73 °C)
Density	13.5336 g/cm³

Energy properties

First ionization energy	10.438 eV
Electron affinity	no data

Atomic structure

Protons	80 (Atomic number)
Neutrons (Hg-202, most abundant isotope)	122
Electrons	80
Electron configuration	[Xe] 6s² 4f¹⁴ 5d¹⁰
Oxidation states	+2, +1
Electronegativity (Pauling)	2
Atomic radius (van der Waals)	209 pm

Ionization energies - NIST ASD (80 states)

State	Charge	Ioniz. energy (eV)	Type
Hg I	0+	10.437504 ± 0.000006	measured
Hg II	1+	18.75688 ± 0.00004	measured
Hg III	2+	34.49 ± 0.05	measured
Hg IV	3+	48.55 ± 0.15	measured
Hg V	4+	61.2 ± 0.2	measured
Hg VI	5+	76.6 ± 0.5	measured
Hg VII	6+	93 ± 2	measured
Hg VIII	7+	113.9 ± 2.1	calculated
Hg IX	8+	134 ± 2.2	calculated
Hg X	9+	153 ± 2.2	calculated
Hg XI	10+	173 ± 2.4	calculated
Hg XII	11+	192.7 ± 1.7	semi-empirical
Hg XIII	12+	276.9 ± 1.1	semi-empirical
Hg XIV	13+	307 ± 15	calculated
Hg XV	14+	332 ± 16	calculated
Hg XVI	15+	357 ± 17	calculated
Hg XVII	16+	402 ± 20	calculated
Hg XVIII	17+	429 ± 21	calculated
Hg XIX	18+	477 ± 24	calculated
Hg XX	19+	530 ± 30	calculated
Hg XXI	20+	560 ± 30	calculated
Hg XXII	21+	590 ± 30	calculated
Hg XXIII	22+	650 ± 30	calculated
Hg XXIV	23+	710 ± 40	calculated
Hg XXV	24+	760 ± 40	calculated
Hg XXVI	25+	820 ± 40	calculated
Hg XXVII	26+	880 ± 40	calculated
Hg XXVIII	27+	930 ± 50	calculated
Hg XXIX	28+	990 ± 50	calculated
Hg XXX	29+	1050 ± 50	calculated
Hg XXXI	30+	1110 ± 60	calculated
Hg XXXII	31+	1160 ± 60	calculated
Hg XXXIII	32+	1220 ± 60	calculated
Hg XXXIV	33+	1280 ± 60	calculated
Hg XXXV	34+	1549 ± 5	calculated
Hg XXXVI	35+	1603 ± 5	calculated
Hg XXXVII	36+	1661 ± 5	calculated
Hg XXXVIII	37+	1723 ± 4	calculated
Hg XXXIX	38+	1780 ± 4	calculated
Hg XL	39+	1839 ± 4	calculated
Hg XLI	40+	1928 ± 4	calculated
Hg XLII	41+	1989 ± 4	calculated
Hg XLIII	42+	2052 ± 4	calculated
Hg XLIV	43+	2113 ± 4	calculated
Hg XLV	44+	2354 ± 4	calculated
Hg XLVI	45+	2412 ± 4	calculated
Hg XLVII	46+	2478 ± 4	calculated
Hg XLVIII	47+	2539 ± 4	calculated
Hg XLIX	48+	2745 ± 4	calculated
Hg L	49+	2815 ± 4	calculated
Hg LI	50+	2981 ± 4	calculated
Hg LII	51+	3049.9 ± 1.5	semi-empirical
Hg LIII	52+	5055 ± 4	calculated
Hg LIV	53+	5191 ± 5	calculated
Hg LV	54+	5335 ± 5	calculated
Hg LVI	55+	5490 ± 5	calculated
Hg LVII	56+	5636 ± 5	calculated
Hg LVIII	57+	5780 ± 6	calculated
Hg LIX	58+	6041 ± 6	calculated
Hg LX	59+	6192 ± 7	calculated
Hg LXI	60+	6356 ± 10	calculated
Hg LXII	61+	6508 ± 12	calculated
Hg LXIII	62+	6933 ± 15	calculated
Hg LXIV	63+	7066 ± 19	calculated
Hg LXV	64+	7211 ± 24	calculated
Hg LXVI	65+	7350 ± 30	calculated
Hg LXVII	66+	8010 ± 40	calculated
Hg LXVIII	67+	8160 ± 40	calculated
Hg LXIX	68+	8470 ± 50	calculated
Hg LXX	69+	8620 ± 50	calculated
Hg LXXI	70+	18550 ± 60	calculated
Hg LXXII	71+	18910 ± 60	calculated
Hg LXXIII	72+	19310 ± 70	calculated
Hg LXXIV	73+	19680 ± 90	calculated
Hg LXXV	74+	22120 ± 90	calculated
Hg LXXVI	75+	22580 ± 100	calculated
Hg LXXVII	76+	23170 ± 110	calculated
Hg LXXVIII	77+	23544.1 ± 0.3	calculated
Hg LXXIX	78+	94124.7 ± 0.3	calculated
Hg LXXX	79+	95898.19 ± 0.22	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: Mercury (Hg) — © images-of-elements.com (CC BY 3.0)

Isotopes (47)

A	N	Half-life	Decay
Hg-170	90	100 μs	α
Hg-171	91	60 μs	α
Hg-172	92	231 μs	α
Hg-173	93	0.80 ms	α
Hg-174	94	1.9 ms	α
Hg-175	95	10.2 ms	α
Hg-176	96	20 ms	α
Hg-177	97	117 ms	α
Hg-178	98	266 ms	α
Hg-179	99	1.05 s	α
Hg-180	100	2.58 s	α
Hg-181	101	3.6 s	α
Hg-182	102	10.88 s	α
Hg-183	103	8.9 s	α
Hg-184	104	30.9 s	EC/β⁺
Hg-185	105	48.2 s	EC/β⁺
Hg-186	106	1.38 min	EC/β⁺
Hg-187	107	1.9 min	EC/β⁺
Hg-188	108	3.25 min	EC/β⁺
Hg-189	109	8.0 min	EC/β⁺
Hg-190	110	20.0 min	EC/β⁺
Hg-191	111	49 min	EC/β⁺
Hg-192	112	4.85 h	EC
Hg-193	113	3.80 h	EC/β⁺
Hg-194	114	450 a	EC
Hg-195	115	10.68 h	EC/β⁺
Hg-196	116	stable	-
Hg-197	117	64.96 h	EC/β⁺
Hg-198	118	stable	-
Hg-199	119	stable	-
Hg-200	120	stable	-
Hg-201	121	stable	-
Hg-202	122	stable	-
Hg-203	123	46.612 d	β⁻
Hg-204	124	stable	-
Hg-205	125	5.1 min	β⁻
Hg-206	126	8.32 min	β⁻
Hg-207	127	2.9 min	β⁻
Hg-208	128	135 s	β⁻
Hg-209	129	6.3 s	β⁻
Hg-210	130	64 s	β⁻
Hg-211	131	26 s	β⁻
Hg-212	132	unknown	β⁻
Hg-213	133	unknown	β⁻
Hg-214	134	unknown	β⁻
Hg-215	135	unknown	β⁻
Hg-216	136	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