Atomic Mass of the Elements

Unit

The atomic mass (ma) is the mass of an atom, typically expressed in atomic mass units (amu) or daltons (Da), where 1 Da equals 1⁄12 the mass of a carbon-12 atom at rest. The protons and neutrons of the nucleus account for nearly all of an atom's mass, so the numeric value in daltons closely approximates the mass number.

Data available for 118 of 118 elements. Highest: Tennessine (294 amu). Lowest: Hydrogen (1.008 amu).

Visualize Atomic Mass in the periodic table →

118 elements

Atomic Mass of the Elements
		Symbol
117	Tennessine	Ts	294
118	Oganesson	Og	294
116	Livermorium	Lv	293
114	Flerovium	Fl	289
115	Moscovium	Mc	289
113	Nihonium	Nh	286
112	Copernicium	Cn	285
111	Roentgenium	Rg	282
110	Darmstadtium	Ds	281
109	Meitnerium	Mt	278
107	Bohrium	Bh	270
106	Seaborgium	Sg	269
108	Hassium	Hs	269
105	Dubnium	Db	268
104	Rutherfordium	Rf	267
103	Lawrencium	Lr	266
102	Nobelium	No	259
101	Mendelevium	Md	258
100	Fermium	Fm	257
99	Einsteinium	Es	252
98	Californium	Cf	251
96	Curium	Cm	247
97	Berkelium	Bk	247
94	Plutonium	Pu	244
95	Americium	Am	243
92	Uranium	U	238
93	Neptunium	Np	237
90	Thorium	Th	232
91	Protactinium	Pa	231
89	Actinium	Ac	227
88	Radium	Ra	226
87	Francium	Fr	223
86	Radon	Rn	222
85	Astatine	At	210
84	Polonium	Po	209
83	Bismuth	Bi	209
82	Lead	Pb	207.2
81	Thallium	Tl	204.4
80	Mercury	Hg	200.6
79	Gold	Au	197
78	Platinum	Pt	195.1
77	Iridium	Ir	192.2
76	Osmium	Os	190.2
75	Rhenium	Re	186.2
74	Tungsten	W	183.8
73	Tantalum	Ta	180.9
72	Hafnium	Hf	178.5
71	Lutetium	Lu	175
70	Ytterbium	Yb	173
69	Thulium	Tm	168.9
68	Erbium	Er	167.3
67	Holmium	Ho	164.9
66	Dysprosium	Dy	162.5
65	Terbium	Tb	158.9
64	Gadolinium	Gd	157.3
63	Europium	Eu	152
62	Samarium	Sm	150.4
61	Promethium	Pm	145
60	Neodymium	Nd	144.2
59	Praseodymium	Pr	140.9
58	Cerium	Ce	140.1
57	Lanthanum	La	138.9
56	Barium	Ba	137.3
55	Cesium	Cs	132.9
54	Xenon	Xe	131.3
52	Tellurium	Te	127.6
53	Iodine	I	126.9
51	Antimony	Sb	121.8
50	Tin	Sn	118.7
49	Indium	In	114.8
48	Cadmium	Cd	112.4
47	Silver	Ag	107.9
46	Palladium	Pd	106.4
45	Rhodium	Rh	102.9
44	Ruthenium	Ru	101.1
43	Technetium	Tc	98
42	Molybdenum	Mo	95.95
41	Niobium	Nb	92.91
40	Zirconium	Zr	91.22
39	Yttrium	Y	88.91
38	Strontium	Sr	87.62
37	Rubidium	Rb	85.47
36	Krypton	Kr	83.8
35	Bromine	Br	79.9
34	Selenium	Se	78.97
33	Arsenic	As	74.92
32	Germanium	Ge	72.63
31	Gallium	Ga	69.72
30	Zinc	Zn	65.38
29	Copper	Cu	63.55
27	Cobalt	Co	58.93
28	Nickel	Ni	58.69
26	Iron	Fe	55.85
25	Manganese	Mn	54.94
24	Chromium	Cr	52
23	Vanadium	V	50.94
22	Titanium	Ti	47.87
21	Scandium	Sc	44.96
20	Calcium	Ca	40.08
18	Argon	Ar	39.95
19	Potassium	K	39.1
17	Chlorine	Cl	35.45
16	Sulfur	S	32.06
15	Phosphorus	P	30.97
14	Silicon	Si	28.09
13	Aluminum	Al	26.98
12	Magnesium	Mg	24.3
11	Sodium	Na	22.99
10	Neon	Ne	20.18
9	Fluorine	F	19
8	Oxygen	O	16
7	Nitrogen	N	14.01
6	Carbon	C	12.01
5	Boron	B	10.81
4	Beryllium	Be	9.012
3	Lithium	Li	6.94
2	Helium	He	4.003
1	Hydrogen	H	1.008

Atomic Mass of the Elements

Related properties