Elements

Properties of individual elements are managed by Element class. Expressions of different elements carry information about their element types, isotope numbers and ionisation states. A comprehensive list of all available elements and their isotopes is given at the end of this section. Examples of element symbols of a carbon atom are given below:

Notation of element symbols

Symbol	Abundance	Ionisation	Note
C	natural	neutral	naturally occuring carbon
C{-3}	natural	cation	positive natural ion
C{+3}	natural	anion	negative natural ion
C{13}	isotope	neutral	carbon-13 isotope
C{13-3}	isotope	cation	positive isotope ion
C{13+3}	isotope	anion	negative isotope ion

The Element class can be used in the following way.

>>> from scinumtools.materials import Element
>>> e = Element('O')
>>> print(e)
Element(O mass=15.999 Z=8.0 N=8.004 e=8.0)
>>> e.Z, e.N, e.e, e.mass
8.0, 8.00448, 8.0, Quantity(1.600e+01 Da)
>>> Element('O{17-2}')
Element(O{17-2} mass=16.998 Z=8 N=9.000 e=6)

The option natural determines how element properties are calculated if isotope number is not specified. By default, its value is set to True. In this case, element values are calculated as a weighted average of all isotopes according to their natural abundances. If set to False, an isotope with the highest abundance is used.

Note

The number of neutrons in naturally abundant elements is not always an integer. This is due to the calculation of averages over all element isotopes.

>>> from scinumtools.materials import Element
>>> Element('O', natural=False)
Element(O mass=15.995 Z=8 N=8.000 e=8)

The option proportion is by default set to one, but it can also hold multiple elements of the same type, e.g. in a substance. If its value is higher than one, all element properties are multiplied correspondingly by this number.

>>> from scinumtools.materials import Element
>>> e = Element('O', proportion=2, natural=False)
>>> print(e)
Element(O2 mass=31.990 Z=16 N=16.000 e=16)
>>> e.proportion, e.element, e.isotope, e.ionisation
2, 'O', 16, 0

Elements can also have properties of matter by adding a density and volume. All properties can be previewed using print() method.

>>> e = Element('B', mass_density=Quantity(997,'kg/m3'), volume=Quantity(1,'l'))
>>> e.print()
Element:

Expression: B
Mass:       10.811
Protons:    5.0
Neutrons:   5.801
Electrons:  5.0

Matter:

Mass density:   Quantity(9.970e-01 g*cm-3)
Number density: Quantity(5.554e+22 cm-3)
Volume:         Quantity(1.000e+00 l)
Mass:           Quantity(9.970e+02 g)

expr      n[cm-3]  rho[g/cm3]            N  M[g]
   B 5.553657e+22       0.997 5.553657e+25 997.0

Individual nucleons can be used in formulas in the same way as elements and have the following properties:

Nucleon properties

Nucleon	Symbol	Z	N	e	Relative atomic mass (Da)
Proton	[p]	1	0	0	1.007276
Neutron	[n]	0	1	0	1.008664
Electron	[e]	0	0	1	5.48579e-4

Symbols of the elements conform to a standard element notation. In the case of named Hydrogen isotopes, it is also possible to use the following short notation:

Special symbols of hydrogen isotopes

Isotope	Symbol	Equivalent
Proton	[p]	H{1-1}
Deuterium	D	H{2}
Tritium	T	H{3}

Below is a list of elements and their corresponding isotopes that can be used with this module. The data was taken from NIST database.

List of available elements

Symbol	Z	A	Relative atomic mass (Da)	Natural abundance
H	1	1	1.00782503223	0.999885
		2	2.01410177812	0.000115
		3	3.0160492779	0.0
He	2	3	3.0160293201	1.34e-06
		4	4.00260325413	0.99999866
Li	3	6	6.0151228874	0.0759
		7	7.0160034366	0.9241
Be	4	9	9.012183065	1.0
B	5	10	10.01293695	0.199
		11	11.00930536	0.801
C	6	12	12.0	0.9893
		13	13.00335483507	0.0107
		14	14.0032419884	0.0
N	7	14	14.00307400443	0.99636
		15	15.00010889888	0.00364
O	8	16	15.99491461957	0.99757
		17	16.9991317565	0.00038
		18	17.99915961286	0.00205
F	9	19	18.99840316273	1.0
Ne	10	20	19.9924401762	0.9048
		21	20.993846685	0.0027
		22	21.991385114	0.0925
Na	11	23	22.989769282	1.0
Mg	12	24	23.985041697	0.7899
		25	24.985836976	0.1
		26	25.982592968	0.1101
Al	13	27	26.98153853	1.0
Si	14	28	27.97692653465	0.92223
		29	28.9764946649	0.04685
		30	29.973770136	0.03092
P	15	31	30.97376199842	1.0
S	16	32	31.9720711744	0.9499
		33	32.9714589098	0.0075
		34	33.967867004	0.0425
		36	35.96708071	0.0001
Cl	17	35	34.968852682	0.7576
		37	36.965902602	0.2424
Ar	18	36	35.967545105	0.003336
		38	37.96273211	0.000629
		40	39.9623831237	0.996035
K	19	39	38.9637064864	0.932581
		40	39.963998166	0.000117
		41	40.9618252579	0.067302
Ca	20	40	39.962590863	0.96941
		42	41.95861783	0.00647
		43	42.95876644	0.00135
		44	43.95548156	0.02086
		46	45.953689	4e-05
		48	47.95252276	0.00187
Sc	21	45	44.95590828	1.0
Ti	22	46	45.95262772	0.0825
		47	46.95175879	0.0744
		48	47.94794198	0.7372
		49	48.94786568	0.0541
		50	49.94478689	0.0518
V	23	50	49.94715601	0.0025
		51	50.94395704	0.9975
Cr	24	50	49.94604183	0.04345
		52	51.94050623	0.83789
		53	52.94064815	0.09501
		54	53.93887916	0.02365
Mn	25	55	54.93804391	1.0
Fe	26	54	53.93960899	0.05845
		56	55.93493633	0.91754
		57	56.93539284	0.02119
		58	57.93327443	0.00282
Co	27	59	58.93319429	1.0
Ni	28	58	57.93534241	0.68077
		60	59.93078588	0.26223
		61	60.93105557	0.011399
		62	61.92834537	0.036346
		64	63.92796682	0.009255
Cu	29	63	62.92959772	0.6915
		65	64.9277897	0.3085
Zn	30	64	63.92914201	0.4917
		66	65.92603381	0.2773
		67	66.92712775	0.0404
		68	67.92484455	0.1845
		70	69.9253192	0.0061
Ga	31	69	68.9255735	0.60108
		71	70.92470258	0.39892
Ge	32	70	69.92424875	0.2057
		72	71.922075826	0.2745
		73	72.923458956	0.0775
		74	73.921177761	0.365
		76	75.921402726	0.0773
As	33	75	74.92159457	1.0
Se	34	74	73.922475934	0.0089
		76	75.919213704	0.0937
		77	76.919914154	0.0763
		78	77.91730928	0.2377
		80	79.9165218	0.4961
		82	81.9166995	0.0873
Br	35	79	78.9183376	0.5069
		81	80.9162897	0.4931
Kr	36	78	77.92036494	0.00355
		80	79.91637808	0.02286
		82	81.91348273	0.11593
		83	82.91412716	0.115
		84	83.9114977282	0.56987
		86	85.9106106269	0.17279
Rb	37	85	84.9117897379	0.7217
		87	86.909180531	0.2783
Sr	38	84	83.9134191	0.0056
		86	85.9092606	0.0986
		87	86.9088775	0.07
		88	87.9056125	0.8258
Y	39	89	88.9058403	1.0
Zr	40	90	89.9046977	0.5145
		91	90.9056396	0.1122
		92	91.9050347	0.1715
		94	93.9063108	0.1738
		96	95.9082714	0.028
Nb	41	93	92.906373	1.0
Mo	42	92	91.90680796	0.1453
		94	93.9050849	0.0915
		95	94.90583877	0.1584
		96	95.90467612	0.1667
		97	96.90601812	0.096
		98	97.90540482	0.2439
		100	99.9074718	0.0982
Tc	43	97	96.9063667	0.0
		98	97.9072124	0.0
		99	98.9062508	0.0
Ru	44	96	95.90759025	0.0554
		98	97.9052868	0.0187
		99	98.9059341	0.1276
		100	99.9042143	0.126
		101	100.9055769	0.1706
		102	101.9043441	0.3155
		104	103.9054275	0.1862
Rh	45	103	102.905498	1.0
Pd	46	102	101.9056022	0.0102
		104	103.9040305	0.1114
		105	104.9050796	0.2233
		106	105.9034804	0.2733
		108	107.9038916	0.2646
		110	109.9051722	0.1172
Ag	47	107	106.9050916	0.51839
		109	108.9047553	0.48161
Cd	48	106	105.9064599	0.0125
		108	107.9041834	0.0089
		110	109.90300661	0.1249
		111	110.90418287	0.128
		112	111.90276287	0.2413
		113	112.90440813	0.1222
		114	113.90336509	0.2873
		116	115.90476315	0.0749
In	49	113	112.90406184	0.0429
		115	114.903878776	0.9571
Sn	50	112	111.90482387	0.0097
		114	113.9027827	0.0066
		115	114.903344699	0.0034
		116	115.9017428	0.1454
		117	116.90295398	0.0768
		118	117.90160657	0.2422
		119	118.90331117	0.0859
		120	119.90220163	0.3258
		122	121.9034438	0.0463
		124	123.9052766	0.0579
Sb	51	121	120.903812	0.5721
		123	122.9042132	0.4279
Te	52	120	119.9040593	0.0009
		122	121.9030435	0.0255
		123	122.9042698	0.0089
		124	123.9028171	0.0474
		125	124.9044299	0.0707
		126	125.9033109	0.1884
		128	127.90446128	0.3174
		130	129.906222748	0.3408
I	53	127	126.9044719	1.0
Xe	54	124	123.905892	0.000952
		126	125.9042983	0.00089
		128	127.903531	0.019102
		129	128.9047808611	0.264006
		130	129.903509349	0.04071
		131	130.90508406	0.212324
		132	131.9041550856	0.269086
		134	133.90539466	0.104357
		136	135.907214484	0.088573
Cs	55	133	132.905451961	1.0
Ba	56	130	129.9063207	0.00106
		132	131.9050611	0.00101
		134	133.90450818	0.02417
		135	134.90568838	0.06592
		136	135.90457573	0.07854
		137	136.90582714	0.11232
		138	137.905247	0.71698
La	57	138	137.9071149	0.0008881
		139	138.9063563	0.9991119
Ce	58	136	135.90712921	0.00185
		138	137.905991	0.00251
		140	139.9054431	0.8845
		142	141.9092504	0.11114
Pr	59	141	140.9076576	1.0
Nd	60	142	141.907729	0.27152
		143	142.90982	0.12174
		144	143.910093	0.23798
		145	144.9125793	0.08293
		146	145.9131226	0.17189
		148	147.9168993	0.05756
		150	149.9209022	0.05638
Pm	61	145	144.9127559	0.0
		147	146.915145	0.0
Sm	62	144	143.9120065	0.0307
		147	146.9149044	0.1499
		148	147.9148292	0.1124
		149	148.9171921	0.1382
		150	149.9172829	0.0738
		152	151.9197397	0.2675
		154	153.9222169	0.2275
Eu	63	151	150.9198578	0.4781
		153	152.921238	0.5219
Gd	64	152	151.9197995	0.002
		154	153.9208741	0.0218
		155	154.9226305	0.148
		156	155.9221312	0.2047
		157	156.9239686	0.1565
		158	157.9241123	0.2484
		160	159.9270624	0.2186
Tb	65	159	158.9253547	1.0
Dy	66	156	155.9242847	0.00056
		158	157.9244159	0.00095
		160	159.9252046	0.02329
		161	160.9269405	0.18889
		162	161.9268056	0.25475
		163	162.9287383	0.24896
		164	163.9291819	0.2826
Ho	67	165	164.9303288	1.0
Er	68	162	161.9287884	0.00139
		164	163.9292088	0.01601
		166	165.9302995	0.33503
		167	166.9320546	0.22869
		168	167.9323767	0.26978
		170	169.9354702	0.1491
Tm	69	169	168.9342179	1.0
Yb	70	168	167.9338896	0.00123
		170	169.9347664	0.02982
		171	170.9363302	0.1409
		172	171.9363859	0.2168
		173	172.9382151	0.16103
		174	173.9388664	0.32026
		176	175.9425764	0.12996
Lu	71	175	174.9407752	0.97401
		176	175.9426897	0.02599
Hf	72	174	173.9400461	0.0016
		176	175.9414076	0.0526
		177	176.9432277	0.186
		178	177.9437058	0.2728
		179	178.9458232	0.1362
		180	179.946557	0.3508
Ta	73	180	179.9474648	0.0001201
		181	180.9479958	0.9998799
W	74	180	179.9467108	0.0012
		182	181.94820394	0.265
		183	182.95022275	0.1431
		184	183.95093092	0.3064
		186	185.9543628	0.2843
Re	75	185	184.9529545	0.374
		187	186.9557501	0.626
Os	76	184	183.9524885	0.0002
		186	185.953835	0.0159
		187	186.9557474	0.0196
		188	187.9558352	0.1324
		189	188.9581442	0.1615
		190	189.9584437	0.2626
		192	191.961477	0.4078
Ir	77	191	190.9605893	0.373
		193	192.9629216	0.627
Pt	78	190	189.9599297	0.00012
		192	191.9610387	0.00782
		194	193.9626809	0.3286
		195	194.9647917	0.3378
		196	195.96495209	0.2521
		198	197.9678949	0.07356
Au	79	197	196.96656879	1.0
Hg	80	196	195.9658326	0.0015
		198	197.9667686	0.0997
		199	198.96828064	0.1687
		200	199.96832659	0.231
		201	200.97030284	0.1318
		202	201.9706434	0.2986
		204	203.97349398	0.0687
Tl	81	203	202.9723446	0.2952
		205	204.9744278	0.7048
Pb	82	204	203.973044	0.014
		206	205.9744657	0.241
		207	206.9758973	0.221
		208	207.9766525	0.524
Bi	83	209	208.9803991	1.0
Po	84	209	208.9824308	0.0
		210	209.9828741	0.0
At	85	210	209.9871479	0.0
		211	210.9874966	0.0
Rn	86	211	210.9906011	0.0
		220	220.0113941	0.0
		222	222.0175782	0.0
Fr	87	223	223.019736	0.0
Ra	88	223	223.0185023	0.0
		224	224.020212	0.0
		226	226.0254103	0.0
		228	228.0310707	0.0
Ac	89	227	227.0277523	0.0
Th	90	230	230.0331341	0.0
		232	232.0380558	1.0
Pa	91	231	231.0358842	1.0
U	92	233	233.0396355	0.0
		234	234.0409523	5.4e-05
		235	235.0439301	0.007204
		236	236.0455682	0.0
		238	238.0507884	0.992742
Np	93	236	236.04657	0.0
		237	237.0481736	0.0
Pu	94	238	238.0495601	0.0
		239	239.0521636	0.0
		240	240.0538138	0.0
		241	241.0568517	0.0
		242	242.0587428	0.0
		244	244.0642053	0.0
Am	95	241	241.0568293	0.0
		243	243.0613813	0.0
Cm	96	243	243.0613893	0.0
		244	244.0627528	0.0
		245	245.0654915	0.0
		246	246.0672238	0.0
		247	247.0703541	0.0
		248	248.0723499	0.0
Bk	97	247	247.0703073	0.0
		249	249.0749877	0.0
Cf	98	249	249.0748539	0.0
		250	250.0764062	0.0
		251	251.0795886	0.0
		252	252.0816272	0.0
Es	99	252	252.08298	0.0
Fm	100	257	257.0951061	0.0
Md	101	258	258.0984315	0.0
		260	260.10365	0.0
No	102	259	259.10103	0.0
Lr	103	262	262.10961	0.0
Rf	104	267	267.12179	0.0
Db	105	268	268.12567	0.0
Sg	106	271	271.13393	0.0
Bh	107	272	272.13826	0.0
Hs	108	270	270.13429	0.0
Mt	109	276	276.15159	0.0
Ds	110	281	281.16451	0.0
Rg	111	280	280.16514	0.0
Cn	112	285	285.17712	0.0
Nh	113	284	284.17873	0.0
Fl	114	289	289.19042	0.0
Mc	115	288	288.19274	0.0
Lv	116	293	293.20449	0.0
Ts	117	292	292.20746	0.0
Og	118	294	294.21392	0.0