4.80					SECTION 4
TABLE 4.16 Table of Nuclides (				Continued	)
					Natural	Cross
					abundance,	section,
Element		A	Half-life		%	barns		Radiation (MeV)
Californium	251	900 y				2.9(2)	10 2	(5.677, 5.851, 6.014)
		252	2.645 y			20.(2)		(6.118, 6.076); L,
								Cm-x; (0.043, 0.100)
Einsteinium	253	20.47 d				186		(6.64); (0.389)
		254	275.7 d			28.(3)		(6.43)
		255	40 d			55		(0.29); (6.26)
Fermium	255	20.1 h				26.(3)		(7.023)
		257	100.5 d					(6.519); L, Cf-x;
								(0.179, 0.241)
Mendelevium	258	51.5 d						(6.718, 6.763);	(0.368)
		260	32 d
Nobelium	255	3.1 min						(8.12, 7.93);	(0.187)
		259	58 min					(7.52, 7.55)
Lawrencium	260	3 min
		261	40 min
		262	3.6 h
Source:	R. B. Firestone and V. S. Shirley, eds.,				Table of Isotopes	, 8th ed., Wiley, New York, 1997, and V. S. Shirley, ed.,
Table of Radioactive Isotopes			, 8th ed., Wiley-Interscience, New York, 1986.

4.9 WORK FUNCTION

TABLE 4.17	Work Functions of the Elements
The work function	is the energy necessary to just remove an electron from the metal surface in thermoelectric
or photoelectric emission. Values are dependent upon the experimental technique (vacua of 10				9 or 10 10 torr,
clean surfaces, and surface conditions including the crystal face identification).
Element	, eV		Element	, eV
Ag	4.64		Eu	2.5
Al	4.19		Fe	4.65
As	(3.75)		Ga	4.25
Au	5.32		Ge	5.0
B	(4.75)		Gd	3.1
Ba	2.35		Hf	3.65
Be	5.08		Hg	4.50
Bi	4.36		In	4.08
C	(5.0)		Ir	5.6
Ca	2.71		K	2.30
Cd	4.12		La	3.40
Ce	2.80		Li	3.10
Co	4.70		Mg	3.66
Cr	4.40		Mn	3.90
Cs	1.90		Mo	4.30
Cu	4.70		Na	2.70

	PROPERTIES OF ATOMS, RADICALS, AND BONDS				4.81
TABLE 4.17 Work Functions of the Elements (		Continued		)
Element	, eV			Element	, eV
Nb	4.20			Si	4.85
Nd	3.1			Sm	2.95
Ni	5.15			Sn	4.35
Os	4.83			Sr	2.76
Pb	4.18			Ta	4.22
Pd	5.00			Tb	3.0
Po	4.6			Te	4.70
Pr	2.7			Th	3.71
Pt	5.40			Ti	4.10
Rb	2.20			Tl	4.02
Re	4.95			U	3.70
Rh	4.98			V	4.44
Ru	4.80			W	4.55
Sb	4.56			Y	3.1
Sc	3.5			Zn	4.30
Se	5.9			Zr	4.00
Source:	S. Trasatti, J. Chem. Soc. Faraday Trans. I	68: 229 (1972); N. D. Lang and W. Kohn, Phys. Rev. B			3: 1215 (1971).

4.10	RELATIVE ABUNDANCES OF NATURALLY
	OCCURRING ISOTOPES
TABLE 4.18 Relative Abundances of Naturally Occurring Isotopes
	Mass			Mass
Element	number	Percent	Element	number	Percent
Aluminum	27	100	Cadmium	112	24.13(14)
Antimony	121	57.21(5)		113	12.22(8)
	123	42.79(5)		114	28.7(3)
Argon	36	0.337(3)		116	7.49(9)
	38	0.063(1)	Calcium	40	96.941(18)
	40	99.600(3)		42	0.647(9)
Arsenic	75	100		43	0.135(6)
Barium	130	0.106(2)		44	2.088(12)
	132	0.101(2)		46	0.004(3)
	134	2.42(3)		48	0.187(4)
	135	6.59(2)	Carbon	12	98.89(1)
	136	7.85(4)		13	1.11(1)
	137	11.23(4)	Cerium	136	0.19(1)
	138	71.70(7)		138	0.25(1)
Beryllium	9	100		140	88.43(10)
Bismuth	209	100		142	11.13(10)
Boron	10	19.9(2)	Cesium	133	100
	11	80.1(2)	Chlorine	35	75.77(7)
Bromine	79	50.69(7)		37	24.23(7)
	81	49.31(7)	Chromium	50	4.345(13)
Cadmium	106	1.25(4)		52	83.79(2)
	108	0.89(2)		53	9.50(2)
	110	12.49(12)		54	2.365(7)
	111	12.80(8)	Cobalt	59	100

4.82		SECTION	4
TABLE 4.18	Relative Abundances of Naturally Occurring Isotopes (				Continued	)
	Mass					Mass
Element	number	Percent		Element		number	Percent
Copper	63	69.17(3)		Krypton		78	0.35(2)
	65	30.83(3)				80	2.25(2)
Dysprosium	156	0.06(1)				82	11.6(1)
	158	0.10(1)				83	11.5(1)
	160	2.34(6)				84	57.0(3)
	161	18.9(2)				86	17.3(2)
	162	25.5(2)		Lanthanum		138	0.0902(2)
	163	24.9(2)				139	99.9098(2)
	164	28.2(2)		Lead		204	1.4(1)
Erbium	162	0.14(1)				206	24.1(1)
	164	1.61(2)				207	22.1(1)
	166	33.6(2)				208	52.4(1)
	167	22.95(15)		Lithium		6	7.5(2)
	168	26.8(2)				7	92.5(2)
	170	14.9(2)		Lutetium		175	97.41(2)
Europium	151	47.8(5)				176	2.59(2)
	153	52.2(5)		Magnesium		24	78.99(3)
Fluorine	19	100				25	10.00(1)
Gadolinium	152	0.20(1)				26	11.01(2)
	154	2.18(3)		Manganese		55	100
	155	14.80(5)		Mercury		196	0.15(1)
	156	20.47(4)				198	9.97(8)
	157	15.65(3)				199	16.87(10)
	158	24.84(12)				200	23.10(16)
	160	21.86(4)				201	13.18(8)
Gallium	69	60.108(9)				202	29.86(20)
	71	39.892(9)				204	6.87(4)
Germanium	70	21.23(4)		Molybdenum		92	14.84(4)
	72	27.66(3)				94	9.25(3)
	73	7.73(1)				95	15.92(5)
	74	35.94(2)				96	16.68(5)
	76	7.44(2)				97	9.55(3)
Gold	197	100				98	24.13(7)
Hafnium	174	0.162(3)				100	9.63(3)
	176	5.206(5)		Neodymium		142	27.13(12)
	177	18.606(13)				143	12.18(6)
	178	27.297(4)				144	23.80(12)
	179	13.629(6)				145	8.30(6)
	180	35.100(7)				146	17.19(9)
Helium	4	100				148	5.76(3)
Holmium	165	100				150	5.64(3)
Hydrogen	1	99.985(1)		Neon		20	90.48(3)
	2	0.015(1)				21	0.27(1)
Indium	113	4.29(2)				22	9.25(3)
	115	95.71(2)		Nickel		58	68.077(9)
Iodine	127	100				60	26.223(8)
Iridium	191	37.27(9)				61	1.140(1)
	193	62.73(9)				62	3.634(2)
Iron	54	5.85(4)				64	0.926(1)
	56	91.75(4)		Niobium		93	100
	57	2.12(1)		Nitrogen		14	99.634(9)
	58	0.26(1)				15	0.366(9)

	PROPERTIES OF ATOMS, RADICALS, AND BONDS					4.83
TABLE 4.18	Relative Abundances of Naturally Occurring Isotopes (			Continued	)
	Mass				Mass
Element	number	Percent	Element		number	Percent
Osmium	184	0.020(3)			78	23.78(9)
	186	1.58(2)			80	49.61(10)
	187	1.6(4)			82	8.73(6)
	188	13.3(1)	Silicon		28	92.23(2)
	189	16.1(1)			29	4.67(2)
	190	26.4(2)			30	3.10(1)
	192	41.0(3)	Silver		107	51.839(7)
Oxygen	16	99.76(1)			109	48.161(7)
	17	0.04	Sodium		23	100
	18	0.20(1)	Strontium		84	0.56(1)
Palladium	102	1.02(1)			86	9.86(1)
	104	11.14(8)			87	7.00(1)
	105	22.33(8)			88	82.58(1)
	106	27.33(3)	Sulfur		32	95.02(9)
	108	26.46(9)			33	0.75(4)
	110	11.72(9)			34	4.21(8)
Phosphorus	31	100			36	0.02(1)
Platinum	190	0.01(1)	Tantalum		180	0.012(2)
	192	0.79(6)			181	99.988(2)
	194	32.9(6)	Tellurium		120	0.096(2)
	195	33.8(6)			122	2.603(4)
	196	25.3(6)			123	0.908(2)
	198	7.2(2)			124	4.816(6)
Potassium	39	93.258(4)			125	7.139(6)
	40	0.0117(1)			126	18.952(11)
	41	6.730(3)			128	31.687(11)
Praseodymium	141	100			130	33.799(10)
Protoactinium	230	100	Terbium		159	100
Rhenium	185	37.40(2)	Thallium		203	29.52(1)
	187	62.60(2)			205	70.48(1)
Rhodium	103	100	Thorium		228	100
Rubidium	85	72.17(2)	Thullium		169	100
	87	27.83(2)	Tin		112	0.97(1)
Ruthenium	96	5.52(6)			114	0.65(1)
	98	1.88(6)			115	0.34(1)
	99	12.7(1)			116	14.53(11)
	100	12.6(1)			117	7.68(7)
	101	17.0(1)			118	24.23(11)
	102	31.6(2)			119	8.59(4)
	104	18.7(2)			120	32.59(10)
Samarium	144	3.1(1)			122	4.63(3)
	147	15.0(2)			124	5.79(5)
	148	11.3(1)	Titanium		46	8.25(3)
	149	13.8(1)			47	7.44(2)
	150	7.4(1)			48	73.72(3)
	152	26.7(2)			49	5.41(2)
	154	22.7(2)			50	5.4(1)
Scandium	45	100	Tungsten		180	0.12(1)
Selenium	74	0.89(2)			182	26.50(3)
	76	9.36(11)			183	14.31(1)
	77	6.63(6)			184	30.64(1)

4.84				SECTION	4
TABLE 4.18		Relative Abundances of Naturally Occurring Isotopes (					Continued	)
			Mass					Mass
Element			number	Percent		Element		number	Percent
Tungsten (	cont.	)	186	28.43(4)				171	14.3(2)
Uranium			234	0.0055(5)				172	21.9(3)
			235	0.720(1)				173	16.12(2)
			238	99.275(2)				174	31.8(4)
Vanadium			50	0.250(2)				176	12.7(2)
			51	99.750(2)		Yttrium		89	100
Xenon			124	0.10(1)		Zinc		64	48.6(3)
			126	0.09(1)				66	27.9(2)
			128	1.91(3)				67	4.1(1)
			129	26.4(6)				68	18.8(4)
			130	4.1(1)				70	0.6(1)
			131	21.2(4)		Zirconium		90	51.45(3)
			132	26.9(5)				91	11.22(4)
			134	10.4(2)				92	17.15(2)
			136	8.9(1)				94	17.38(4)
Ytterbium			168	0.13(1)				96	2.80(2)
			170	3.05(6)
Source:	A. H. Wapstra and G. Audi,			“The 1983 Atomic Mass Evaluation,”			Nucl. Phys.,	A432:1-54	(1985) and references
cited for Table 4.16.