Click a column title, such as Symbol, to sort the table by that item.
Electron
configuration
1 
1.0079
Hydrogen
H
-259
-253
0.09
0.14
1776
1
1s1
13.5984
2 
4.0026
Helium
He
-272
-269
0.18 
1895
18
1s2
24.5874
3 
6.941
Lithium
Li
180
1347
0.53 
1817
1
[He] 2s1
5.3917
4 
9.0122
Beryllium
Be
1278
2970
1.85 
1797
2
[He] 2s2
9.3227
5 
10.811
Boron
B
2300
2550
2.34 
1808
13
[He] 2s2 2p1
8.298
6 
12.0107
Carbon
C
3500
4827
2.26
0.094
ancient
14
[He] 2s2 2p2
11.2603
7 
14.0067
Nitrogen
N
-210
-196
1.25 
1772
15
[He] 2s2 2p3
14.5341
8 
15.9994
Oxygen
O
-218
-183
1.43
46.71
1774
16
[He] 2s2 2p4
13.6181
9 
18.9984
Fluorine
F
-220
-188
1.7
0.029
1886
17
[He] 2s2 2p5
17.4228
10 
20.1797
Neon
Ne
-249
-246
0.9 
1898
18
[He] 2s2 2p6
21.5645
11 
22.9897
Sodium
Na
98
883
0.97
2.75
1807
1
[Ne] 3s1
5.1391
12 
24.305
Magnesium
Mg
639
1090
1.74
2.08
1755
2
[Ne] 3s2
7.6462
13 
26.9815
Aluminum
Al
660
2467
2.7
8.07
1825
13
[Ne] 3s2 3p1
5.9858
14 
28.0855
Silicon
Si
1410
2355
2.33
27.69
1824
14
[Ne] 3s2 3p2
8.1517
15 
30.9738
Phosphorus
P
44
280
1.82
0.13
1669
15
[Ne] 3s2 3p3
10.4867
16 
32.065
Sulfur
S
113
445
2.07
0.052
ancient
16
[Ne] 3s2 3p4
10.36
17 
35.453
Chlorine
Cl
-101
-35
3.21
0.045
1774
17
[Ne] 3s2 3p5
12.9676
18 
39.948
Argon
Ar
-189
-186
1.78 
1894
18
[Ne] 3s2 3p6
15.7596
19 
39.0983
Potassium
K
64
774
0.86
2.58
1807
1
[Ar] 4s1
4.3407
20 
40.078
Calcium
Ca
839
1484
1.55
3.65
1808
2
[Ar] 4s2
6.1132
21 
44.9559
Scandium
Sc
1539
2832
2.99 
1879
3
[Ar] 3d1 4s2
6.5615
22 
47.867
Titanium
Ti
1660
3287
4.54
0.62
1791
4
[Ar] 3d2 4s2
6.8281
23 
50.9415
Vanadium
V
1890
3380
6.11 
1830
5
[Ar] 3d3 4s2
6.7462
24 
51.9961
Chromium
Cr
1857
2672
7.19
0.035
1797
6
[Ar] 3d5 4s1
6.7665
25 
54.938
Manganese
Mn
1245
1962
7.43
0.09
1774
7
[Ar] 3d5 4s2
7.434
26 
55.845
Iron
Fe
1535
2750
7.87
5.05
ancient
8
[Ar] 3d6 4s2
7.9024
27 
58.9332
Cobalt
Co
1495
2870
8.9 
1735
9
[Ar] 3d7 4s2
7.881
28 
58.6934
Nickel
Ni
1453
2732
8.9
0.019
1751
10
[Ar] 3d8 4s2
7.6398
29 
63.546
Copper
Cu
1083
2567
8.96 
ancient
11
[Ar] 3d10 4s1
7.7264
30 
65.39
Zinc
Zn
420
907
7.13 
ancient
12
[Ar] 3d10 4s2
9.3942
31 
69.723
Gallium
Ga
30
2403
5.91 
1875
13
[Ar] 3d10 4s2 4p1
5.9993
32 
72.64
Germanium
Ge
937
2830
5.32 
1886
14
[Ar] 3d10 4s2 4p2
7.8994
33 
74.9216
Arsenic
As
81
613
5.72 
ancient
15
[Ar] 3d10 4s2 4p3
9.7886
34 
78.96
Selenium
Se
217
685
4.79 
1817
16
[Ar] 3d10 4s2 4p4
9.7524
35 
79.904
Bromine
Br
-7
59
3.12 
1826
17
[Ar] 3d10 4s2 4p5
11.8138
36 
83.8
Krypton
Kr
-157
-153
3.75 
1898
18
[Ar] 3d10 4s2 4p6
13.9996
37 
85.4678
Rubidium
Rb
39
688
1.63 
1861
1
[Kr] 5s1
4.1771
38 
87.62
Strontium
Sr
769
1384
2.54 
1790
2
[Kr] 5s2
5.6949
39 
88.9059
Yttrium
Y
1523
3337
4.47 
1794
3
[Kr] 4d1 5s2
6.2173
40 
91.224
Zirconium
Zr
1852
4377
6.51
0.025
1789
4
[Kr] 4d2 5s2
6.6339
41 
92.9064
Niobium
Nb
2468
4927
8.57 
1801
5
[Kr] 4d4 5s1
6.7589
42 
95.94
Molybdenum
Mo
2617
4612
10.22 
1781
6
[Kr] 4d5 5s1
7.0924
43
*
98
Technetium
Tc
2200
4877
11.5 
1937
7
[Kr] 4d5 5s2
7.28
44 
101.07
Ruthenium
Ru
2250
3900
12.37 
1844
8
[Kr] 4d7 5s1
7.3605
45 
102.9055
Rhodium
Rh
1966
3727
12.41 
1803
9
[Kr] 4d8 5s1
7.4589
46 
106.42
Palladium
Pd
1552
2927
12.02 
1803
10
[Kr] 4d10
8.3369
47 
107.8682
Silver
Ag
962
2212
10.5 
ancient
11
[Kr] 4d10 5s1
7.5762
48 
112.411
Cadmium
Cd
321
765
8.65 
1817
12
[Kr] 4d10 5s2
8.9938
49 
114.818
Indium
In
157
2000
7.31 
1863
13
[Kr] 4d10 5s2 5p1
5.7864
50 
118.71
Tin
Sn
232
2270
7.31 
ancient
14
[Kr] 4d10 5s2 5p2
7.3439
51 
121.76
Antimony
Sb
630
1750
6.68 
ancient
15
[Kr] 4d10 5s2 5p3
8.6084
52 
127.6
Tellurium
Te
449
990
6.24 
1783
16
[Kr] 4d10 5s2 5p4
9.0096
53 
126.9045
Iodine
I
114
184
4.93 
1811
17
[Kr] 4d10 5s2 5p5
10.4513
54 
131.293
Xenon
Xe
-112
-108
5.9 
1898
18
[Kr] 4d10 5s2 5p6
12.1298
55 
132.9055
Cesium
Cs
29
678
1.87 
1860
1
[Xe] 6s1
3.8939
56 
137.327
Barium
Ba
725
1140
3.59
0.05
1808
2
[Xe] 6s2
5.2117
57 
138.9055
Lanthanum
La
920
3469
6.15 
1839
3
[Xe] 5d1 6s2
5.5769
58 
140.116
Cerium
Ce
795
3257
6.77 
1803
101
[Xe] 4f1 5d1 6s2
5.5387
59 
140.9077
Praseodymium
Pr
935
3127
6.77 
1885
101
[Xe] 4f3 6s2
5.473
60 
144.24
Neodymium
Nd
1010
3127
7.01 
1885
101
[Xe] 4f4 6s2
5.525
61
*
145
Promethium
Pm
1100
3000
7.3 
1945
101
[Xe] 4f5 6s2
5.582
62 
150.36
Samarium
Sm
1072
1900
7.52 
1879
101
[Xe] 4f6 6s2
5.6437
63 
151.964
Europium
Eu
822
1597
5.24 
1901
101
[Xe] 4f7 6s2
5.6704
64 
157.25
Gadolinium
Gd
1311
3233
7.9 
1880
101
[Xe] 4f7 5d1 6s2
6.1501
65 
158.9253
Terbium
Tb
1360
3041
8.23 
1843
101
[Xe] 4f9 6s2
5.8638
66 
162.5
Dysprosium
Dy
1412
2562
8.55 
1886
101
[Xe] 4f10 6s2
5.9389
67 
164.9303
Holmium
Ho
1470
2720
8.8 
1867
101
[Xe] 4f11 6s2
6.0215
68 
167.259
Erbium
Er
1522
2510
9.07 
1842
101
[Xe] 4f12 6s2
6.1077
69 
168.9342
Thulium
Tm
1545
1727
9.32 
1879
101
[Xe] 4f13 6s2
6.1843
70 
173.04
Ytterbium
Yb
824
1466
6.9 
1878
101
[Xe] 4f14 6s2
6.2542
71 
174.967
Lutetium
Lu
1656
3315
9.84 
1907
101
[Xe] 4f14 5d1 6s2
5.4259
72 
178.49
Hafnium
Hf
2150
5400
13.31 
1923
4
[Xe] 4f14 5d2 6s2
6.8251
73 
180.9479
Tantalum
Ta
2996
5425
16.65 
1802
5
[Xe] 4f14 5d3 6s2
7.5496
74 
183.84
Tungsten
W
3410
5660
19.35 
1783
6
[Xe] 4f14 5d4 6s2
7.864
75 
186.207
Rhenium
Re
3180
5627
21.04 
1925
7
[Xe] 4f14 5d5 6s2
7.8335
76 
190.23
Osmium
Os
3045
5027
22.6 
1803
8
[Xe] 4f14 5d6 6s2
8.4382
77 
192.217
Iridium
Ir
2410
4527
22.4 
1803
9
[Xe] 4f14 5d7 6s2
8.967
78 
195.078
Platinum
Pt
1772
3827
21.45 
1735
10
[Xe] 4f14 5d9 6s1
8.9587
79 
196.9665
Gold
Au
1064
2807
19.32 
ancient
11
[Xe] 4f14 5d10 6s1
9.2255
80 
200.59
Hg
-39
357
13.55 
ancient
12
[Xe] 4f14 5d10 6s2
10.4375
81 
204.3833
Thallium
Tl
303
1457
11.85 
1861
13
[Xe] 4f14 5d10 6s2 6p1
6.1082
82 
207.2
Lead
Pb
327
1740
11.35 
ancient
14
[Xe] 4f14 5d10 6s2 6p2
7.4167
83 
208.9804
Bismuth
Bi
271
1560
9.75 
ancient
15
[Xe] 4f14 5d10 6s2 6p3
7.2856
84
*
209
Polonium
Po
254
962
9.3 
1898
16
[Xe] 4f14 5d10 6s2 6p4
8.417
85
*
210
Astatine
At
302
337  
1940
17
[Xe] 4f14 5d10 6s2 6p5
9.3
86
*
222
Radon
Rn
-71
-62
9.73 
1900
18
[Xe] 4f14 5d10 6s2 6p6
10.7485
87
*
223
Francium
Fr
27
677  
1939
1
[Rn] 7s1
4.0727
88
*
226
Radium
Ra
700
1737
5.5 
1898
2
[Rn] 7s2
5.2784
89
*
227
Actinium
Ac
1050
3200
10.07 
1899
3
[Rn] 6d1 7s2
5.17
90 
232.0381
Thorium
Th
1750
4790
11.72 
1829
102
[Rn] 6d2 7s2
6.3067
91 
231.0359
Protactinium
Pa
1568 
15.4 
1913
102
[Rn] 5f2 6d1 7s2
5.89
92 
238.0289
Uranium
U
1132
3818
18.95 
1789
102
[Rn] 5f3 6d1 7s2
6.1941
93
*
237
Neptunium
Np
640
3902
20.2 
1940
102
[Rn] 5f4 6d1 7s2
6.2657
94
*
244
Plutonium
Pu
640
3235
19.84 
1940
102
[Rn] 5f6 7s2
6.0262
95
*
243
Americium
Am
994
2607
13.67 
1944
102
[Rn] 5f7 7s2
5.9738
96
*
247
Curium
Cm
1340 
13.5 
1944
102 
5.9915
97
*
247
Berkelium
Bk
986 
14.78 
1949
102 
6.1979
98
*
251
Californium
Cf
900 
15.1 
1950
102 
6.2817
99
*
252
Einsteinium
Es
860   
1952
102 
6.42
100
*
257
Fermium
Fm
1527   
1952
102 
6.5
101
*
258
Mendelevium
Md    
1955
102 
6.58
102
*
259
Nobelium
No
827   
1958
102 
6.65
103
*
262
Lawrencium
Lr
1627   
1961
102 
4.9
104
*
261
Rutherfordium
Rf    
1964
4  
105
*
262
Dubnium
Db    
1967
5  
106
*
266
Seaborgium
Sg    
1974
6  
107
*
264
Bohrium
Bh    
1981
7  
108
*
277
Hassium
Hs    
1984
8  
109
*
268
Meitnerium
Mt    
1982
9  
 
It is Hydrogen, with a atomic symbol of 'H'
The mass number is the sum of protons and neutrons in the atomic nucleus of chemical elements. All mass numbers are integers. The atomic weight is not an an integer because is calculated taking in the account the isotopic composition of an element; also the mass excess has a role.
Yes, it must be used as all elements have one or more isotopes and all elements have an atomic mass.
Atomic mass
The atomic mass of iodine is less than the atomic mass of all elements with greater atomic number.
All elements have an atomic mass relative to 12C having a mass of 12.
All chemical elements have atomic numbers.
The mass number is the sum of protons and neutrons in the atomic nucleus of chemical elements. All mass numbers are integers. The atomic weight is not an an integer because is calculated taking in the account the isotopic composition of an element; also the mass excess has a role.
Yes, it must be used as all elements have one or more isotopes and all elements have an atomic mass.
1. All the atomic numbers are whole numbers. 2. If you think to atomic weight of heavy radioactive elements (atomic numbers from 93 to 118) is a rule of IUPAC to indicate in square parenthesis, [], the atomic mass of the most stable or known isotope.
Atomic mass
All elements have an (atomic) weight or mass.
The atomic mass of iodine is less than the atomic mass of all elements with greater atomic number.
All elements have an atomic mass relative to 12C having a mass of 12.
If "element 5" in this question means the element with atomic number 5, then all of the elements with atomic numbers 1 through 4 have smaller atomic masses. These elements are hydrogen, helium, lithium, and beryllium.
The mass number of an isotope of an element is equal to its atomic mass number. However, the atomic weight of an element is a weighted average of the isotopes that occur in the element in nature. Because almost all elements have more than one naturally occurring isotope (if they have any), the atomic weights of most elements are not integers, as mass numbers always are.
First of all, an atom can not literally have either more than one mass number or more than one atomic number. Different atoms of the same element can have different mass numbers but the same atomic number because the atomic number is the defining characteristic of an element, but many elements have isotopes that have different numbers of neutrons in their nuclei and therefore different mass numbers: Mass numbers are the sum of the numbers of protons and neutrons in the nucleus.
The molar mass of any element is its atomic weight in grams. The atomic weights of the elements are found on the periodic table.