Molar ionization energies of the elements

These tables list values of molar ionization energies, measured in kJ mol-1. This is the energy per mole necessary to remove electrons from gaseous atoms or atomic ions. The first molar ionization energy applies to the neutral atoms. The second, third, etc., molar ionization energy applies to the further removal of an electron from a singly, doubly, etc., charged ion. For ionization energies measured in the unit eV, see Ionization energies of the elements (data page).

Contents

1st–10th

number symbol name 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
1 H hydrogen 1312.0
2 He helium 2372.3 5250.5
3 Li lithium 520.2 7298.1 11815.0
4 Be beryllium 899.5 1757.1 14848.7 21006.6
5 B boron 800.6 2427.1 3659.7 25025.8 32826.7
6 C carbon 1086.5 2352.6 4620.5 6222.7 37831 47277.0
7 N nitrogen 1402.3 2856 4578.1 7475.0 9444.9 53266.6 64360
8 O oxygen 1313.9 3388.3 5300.5 7469.2 10989.5 13326.5 71330 84078.0
9 F fluorine 1681.0 3374.2 6050.4 8407.7 11022.7 15164.1 17868 92038.1 106434.3
10 Ne neon 2080.7 3952.3 6122 9371 12177 15238 19999.0 23069.5 115379.5 131432
11 Na sodium 495.8 4562 6910.3 9543 13354 16613 20117 25496 28932 141362
12 Mg magnesium 737.7 1450.7 7732.7 10542.5 13630 18020 21711 25661 31653 35458
13 Al aluminium 577.5 1816.7 2744.8 11577 14842 18379 23326 27465 31853 38473
14 Si silicon 786.5 1577.1 3231.6 4355.5 16091 19805 23780 29287 33878 38726
15 P phosphorus 1011.8 1907 2914.1 4963.6 6273.9 21267 25431 29872 35905 40950
16 S sulfur 999.6 2252 3357 4556 7004.3 8495.8 27107 31719 36621 43177
17 Cl chlorine 1251.2 2298 3822 5158.6 6542 9362 11018 33604 38600 43961
18 Ar argon 1520.6 2665.8 3931 5771 7238 8781 11995 13842 40760 46186
19 K potassium 418.8 3052 4420 5877 7975 9590 11343 14944 16963.7 48610
20 Ca calcium 589.8 1145.4 4912.4 6491 8153 10496 12270 14206 18191 20385
21 Sc scandium 633.1 1235.0 2388.6 7090.6 8843 10679 13310 15250 17370 21726
22 Ti titanium 658.8 1309.8 2652.5 4174.6 9581 11533 13590 16440 18530 20833
23 V vanadium 650.9 1414 2830 4507 6298.7 12363 14530 16730 19860 22240
24 Cr chromium 652.9 1590.6 2987 4743 6702 8744.9 15455 17820 20190 23580
25 Mn manganese 717.3 1509.0 3248 4940 6990 9220 11500 18770 21400 23960
26 Fe iron 762.5 1561.9 2957 5290 7240 9560 12060 14580 22540 25290
27 Co cobalt 760.4 1648 3232 4950 7670 9840 12440 15230 17959 26570
28 Ni nickel 737.1 1753.0 3395 5300 7339 10400 12800 15600 18600 21670
29 Cu copper 745.5 1957.9 3555 5536 7700 9900 13400 16000 19200 22400
30 Zn zinc 906.4 1733.3 3833 5731 7970 10400 12900 16800 19600 23000
31 Ga gallium 578.8 1979.3 2963 6180
32 Ge germanium 762 1537.5 3302.1 4411 9020
33 As arsenic 947.0 1798 2735 4837 6043 12310
34 Se selenium 941.0 2045 2973.7 4144 6590 7880 14990
35 Br bromine 1139.9 2103 3470 4560 5760 8550 9940 18600
36 Kr krypton 1350.8 2350.4 3565 5070 6240 7570 10710 12138 22274 25880
37 Rb rubidium 403.0 2633 3860 5080 6850 8140 9570 13120 14500 26740
38 Sr strontium 549.5 1064.2 4138 5500 6910 8760 10230 11800 15600 17100
39 Y yttrium 600 1180 1980 5847 7430 8970 11190 12450 14110 18400
40 Zr zirconium 640.1 1270 2218 3313 7752 9500
41 Nb niobium 652.1 1380 2416 3700 4877 9847 12100
42 Mo molybdenum 684.3 1560 2618 4480 5257 6640.8 12125 13860 15835 17980
43 Tc technetium 702 1470 2850
44 Ru ruthenium 710.2 1620 2747
45 Rh rhodium 719.7 1740 2997
46 Pd palladium 804.4 1870 3177
47 Ag silver 731.0 2070 3361
48 Cd cadmium 867.8 1631.4 3616
49 In indium 558.3 1820.7 2704 5210
50 Sn tin 708.6 1411.8 2943.0 3930.3 7456
51 Sb antimony 834 1594.9 2440 4260 5400 10400
52 Te tellurium 869.3 1790 2698 3610 5668 6820 13200
53 I iodine 1008.4 1845.9 3180
54 Xe xenon 1170.4 2046.4 3099.4
55 Cs caesium 375.7 2234.3 3400
56 Ba barium 502.9 965.2 3600
57 La lanthanum 538.1 1067 1850.3 4819 5940
58 Ce cerium 534.4 1050 1949 3547 6325 7490
59 Pr praseodymium 527 1020 2086 3761 5551
60 Nd neodymium 533.1 1040 2130 3900
61 Pm promethium 540 1050 2150 3970
62 Sm samarium 544.5 1070 2260 3990
63 Eu europium 547.1 1085 2404 4120
64 Gd gadolinium 593.4 1170 1990 4250
65 Tb terbium 565.8 1110 2114 3839
66 Dy dysprosium 573.0 1130 2200 3990
67 Ho holmium 581.0 1140 2204 4100
68 Er erbium 589.3 1150 2194 4120
69 Tm thulium 596.7 1160 2285 4120
70 Yb ytterbium 603.4 1174.8 2417 4203
71 Lu lutetium 523.5 1340 2022.3 4370 6445
72 Hf hafnium 658.5 1440 2250 3216
73 Ta tantalum 761 1500
74 W tungsten 770 1700
75 Re rhenium 760 1260 2510 3640
76 Os osmium 840 1600
77 Ir iridium 880 1600
78 Pt platinum 870 1791
79 Au gold 890.1 1980
80 Hg mercury 1007.1 1810 3300
81 Tl thallium 589.4 1971 2878
82 Pb lead 715.6 1450.5 3081.5 4083 6640
83 Bi bismuth 703 1610 2466 4370 5400 8520
84 Po polonium 812.1
85 At astatine 890±40
86 Rn radon 1037
87 Fr francium 380
88 Ra radium 509.3 979.0
89 Ac actinium 499 1170
90 Th thorium 587 1110 1930 2780
91 Pa protactinium 568
92 U uranium 597.6 1420
93 Np neptunium 604.5
94 Pu plutonium 584.7
95 Am americium 578
96 Cm curium 581
97 Bk berkelium 601
98 Cf californium 608
99 Es einsteinium 619
100 Fm fermium 627
101 Md mendelevium 635
102 No nobelium 642
103 Lr lawrencium 470
104 Rf rutherfordium 580

11th–20th

number symbol name 11th 12th 13th 14th 15th 16th 17th 18th 19th 20th
11 Na sodium 159076
12 Mg magnesium 169988 189368
13 Al aluminium 42647 223366 (201266) should be less than 13th 222316
14 Si silicon 45962 50502 235196 257923
15 P phosphorus 46261 54110 59024 271791 296195
16 S sulfur 48710 54460 62930 68216 311048 337138
17 Cl chlorine 51068 57119 63363 72341 78095 352994 380760
18 Ar argon 52002 59653 66199 72918 82473 88576 397605 427066
19 K potassium 54490 60730 68950 75900 83080 93400 99710 444880 476063
20 Ca calcium 57110 63410 70110 78890 86310 94000 104900 111711 494850 527762
21 Sc scandium 24102 66320 73010 80160 89490 97400 105600 117000 124270 547530
22 Ti titanium 25575 28125 76015 83280 90880 100700 109100 117800 129900 137530
23 V vanadium 24670 29730 32446 86450 94170 102300 112700 121600 130700 143400
24 Cr chromium 26130 28750 34230 37066 97510 105800 114300 125300 134700 144300
25 Mn manganese 27590 30330 33150 38880 41987 109480 118100 127100 138600 148500
26 Fe iron 28000 31920 34830 37840 44100 47206 122200 131000 140500 152600
27 Co cobalt 29400 32400 36600 39700 42800 49396 52737 134810 145170 154700
28 Ni nickel 30970 34000 37100 41500 44800 48100 55101 58570 148700 159000
29 Cu copper 25600 35600 38700 42000 46700 50200 53700 61100 64702 163700
30 Zn zinc 26400 29990 40490 43800 47300 52300 55900 59700 67300 71200
36 Kr krypton 29700 33800 37700 43100 47500 52200 57100 61800 75800 80400
38 Sr strontium 31270
39 Y yttrium 19900 36090
42 Mo molybdenum 20190 22219 26930 29196 52490 55000 61400 67700 74000 80400

21st–30th

number symbol name 21st 22nd 23rd 24th 25th 26th 27th 28th 29th 30th
21 Sc scandium 582163
22 Ti titanium 602930 639294
23 V vanadium 151440 661050 699144
24 Cr chromium 157700 166090 721870 761733
25 Mn manganese 158600 172500 181380 785450 827067
26 Fe iron 163000 173600 188100 195200 851800 895161
27 Co cobalt 167400 178100 189300 204500 214100 920870 966023
28 Ni nickel 169400 182700 194000 205600 221400 231490 992718 1039668
29 Cu copper 174100 184900 198800 210500 222700 239100 249660 1067358 1116105
30 Zn zinc 179100
36 Kr krypton 85300 90400 96300 101400 111100 116290 282500 296200 311400 326200
42 Mo molybdenum 87000 93400 98420 104400 121900 127700 133800 139800 148100 154500

References