Element: Plutonium

General data

Element name	Plutonium
Chemical symbol	Pu
Atomic number Z	94
Year discovered	1940
Standard state (25°C)	Solid
Category	Actinide
Block	f
Atomic mass	[244]
CPK color	#006BFF

Physical properties

Melting point	913 K (640 °C)
Boiling point	3501 K (3228 °C)
Density	19.84 g/cm³

Energy properties

First ionization energy	6.06 eV
Electron affinity	no data

Atomic structure

Protons	94 (Atomic number)
Neutrons (Pu-244, longest-lived isotope)	150
Electrons	94
Electron configuration	[Rn] 7s² 5f⁶
Oxidation states	+6, +5, +4, +3
Electronegativity (Pauling)	1.28
Atomic radius (van der Waals)	243 pm

Ionization energies - NIST ASD (94 states)

State	Charge	Ioniz. energy (eV)	Type
Pu I	0+	6.02576 ± 0.00025	measured
Pu II	1+	11.5 ± 0.4	semi-empirical
Pu III	2+	21.1 ± 0.4	semi-empirical
Pu IV	3+	35 ± 0.4	semi-empirical
Pu V	4+	49 ± 1.9	calculated
Pu VI	5+	80 ± 4	calculated
Pu VII	6+	95 ± 5	calculated
Pu VIII	7+	109 ± 5	calculated
Pu IX	8+	124 ± 6	calculated
Pu X	9+	139 ± 7	calculated
Pu XI	10+	159 ± 8	calculated
Pu XII	11+	179 ± 9	calculated
Pu XIII	12+	200 ± 3	calculated
Pu XIV	13+	219 ± 3	calculated
Pu XV	14+	258 ± 3	calculated
Pu XVI	15+	278 ± 3	calculated
Pu XVII	16+	389 ± 3	calculated
Pu XVIII	17+	416 ± 3	calculated
Pu XIX	18+	444 ± 3	calculated
Pu XX	19+	474 ± 4	calculated
Pu XXI	20+	503 ± 4	calculated
Pu XXII	21+	532 ± 4	calculated
Pu XXIII	22+	575 ± 4	calculated
Pu XXIV	23+	605 ± 4	calculated
Pu XXV	24+	637 ± 4	calculated
Pu XXVI	25+	668 ± 4	calculated
Pu XXVII	26+	820 ± 40	calculated
Pu XXVIII	27+	850 ± 40	calculated
Pu XXIX	28+	890 ± 40	calculated
Pu XXX	29+	930 ± 50	calculated
Pu XXXI	30+	1030 ± 50	calculated
Pu XXXII	31+	1070 ± 50	calculated
Pu XXXIII	32+	1180 ± 60	calculated
Pu XXXIV	33+	1220 ± 60	calculated
Pu XXXV	34+	1340 ± 70	calculated
Pu XXXVI	35+	1420 ± 70	calculated
Pu XXXVII	36+	1500 ± 70	calculated
Pu XXXVIII	37+	1580 ± 70	calculated
Pu XXXIX	38+	1660 ± 80	calculated
Pu XL	39+	1740 ± 90	calculated
Pu XLI	40+	1820 ± 90	calculated
Pu XLII	41+	1890 ± 90	calculated
Pu XLIII	42+	1990 ± 100	calculated
Pu XLIV	43+	2070 ± 100	calculated
Pu XLV	44+	2150 ± 110	calculated
Pu XLVI	45+	2230 ± 110	calculated
Pu XLVII	46+	2310 ± 110	calculated
Pu XLVIII	47+	2390 ± 120	calculated
Pu XLIX	48+	2774 ± 4	calculated
Pu L	49+	2844 ± 4	calculated
Pu LI	50+	2918 ± 4	calculated
Pu LII	51+	2997 ± 4	calculated
Pu LIII	52+	3072 ± 4	calculated
Pu LIV	53+	3146 ± 5	calculated
Pu LV	54+	3290 ± 5	calculated
Pu LVI	55+	3366 ± 5	calculated
Pu LVII	56+	3449 ± 5	calculated
Pu LVIII	57+	3527 ± 6	calculated
Pu LIX	58+	3836 ± 6	calculated
Pu LX	59+	3911 ± 7	calculated
Pu LXI	60+	3993 ± 10	calculated
Pu LXII	61+	4068 ± 12	calculated
Pu LXIII	62+	4496 ± 15	calculated
Pu LXIV	63+	4585 ± 19	calculated
Pu LXV	64+	4807 ± 24	calculated
Pu LXVI	65+	4890 ± 30	calculated
Pu LXVII	66+	7830 ± 40	calculated
Pu LXVIII	67+	7990 ± 40	calculated
Pu LXIX	68+	8170 ± 50	calculated
Pu LXX	69+	8360 ± 50	calculated
Pu LXXI	70+	8540 ± 60	calculated
Pu LXXII	71+	8710 ± 60	calculated
Pu LXXIII	72+	9130 ± 70	calculated
Pu LXXIV	73+	9310 ± 90	calculated
Pu LXXV	74+	9520 ± 90	calculated
Pu LXXVI	75+	9700 ± 100	calculated
Pu LXXVII	76+	10230 ± 110	calculated
Pu LXXVIII	77+	10390 ± 120	calculated
Pu LXXIX	78+	10570 ± 120	calculated
Pu LXXX	79+	10730 ± 140	calculated
Pu LXXXI	80+	12060 ± 150	calculated
Pu LXXXII	81+	12260 ± 160	calculated
Pu LXXXIII	82+	12660 ± 170	calculated
Pu LXXXIV	83+	12840 ± 190	calculated
Pu LXXXV	84+	26480 ± 200	calculated
Pu LXXXVI	85+	26920 ± 220	calculated
Pu LXXXVII	86+	27400 ± 240	calculated
Pu LXXXVIII	87+	27840 ± 250	calculated
Pu LXXXIX	88+	32800 ± 300	calculated
Pu XC	89+	33400 ± 300	calculated
Pu XCI	90+	34100 ± 300	calculated
Pu XCII	91+	34625.8 ± 0.7	calculated
Pu XCIII	92+	136305.1 ± 2.4	calculated
Pu XCIV	93+	138640.2 ± 2.5	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: Plutonium (Pu) — © images-of-elements.com (CC BY 3.0)

Isotopes (20)

A	N	Half-life	Decay
Pu-228	134	1.1 s	α
Pu-229	135	80 s	α
Pu-230	136	107 s	α
Pu-231	137	8.6 min	EC/β⁺
Pu-232	138	33.1 min	EC
Pu-233	139	20.9 min	EC/β⁺
Pu-234	140	8.8 h	EC
Pu-235	141	25.3 min	EC/β⁺
Pu-236	142	2.858 a	α
Pu-237	143	45.64 d	EC
Pu-238	144	87.7 a	α
Pu-239	145	24109 a	α
Pu-240	146	6562 a	α
Pu-241	147	14.33 a	β⁻
Pu-242	148	3.750×10⁵ a	α
Pu-243	149	4.955 h	β⁻
Pu-244	150	8.13×10⁷ a	α
Pu-245	151	10.54 h	β⁻
Pu-246	152	10.84 d	β⁻
Pu-247	153	2.27 d	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