All sources concur with the data above except in the separately listed instances:

• NIST
  • http://physics.nist.gov/PhysRefData/IonEnergy/ionEnergy.html ; retrieved July 2005, (elements 1-104) อ้างต้นฉบับ ได้แก่
  • Atomic Spectroscopy, by W.C. Martin and W.L. Wiese in Atomic, Molecular, & Optical Physics Handbook, ed. by G.W.F. Drake (AIP, Woodbury, NY, 1996) Chapter 10, pp. 135-153.

โดย CRC Handbook บทที่ 1 subsection Electron Configuration of Neutral Atoms in the Ground State.

• • 91 Pa : [Rn] 5f2(3H4) 6d 7s2
  • 92 U : [Rn] 5f3(4Io9/2) 6d 7s2
  • 93 Np : [Rn] 5f4(5I4) 6d 7s2
  • 103 Lr : [Rn] 5f14 7s2 7p1 question-marked
  • 104 Rf : [Rn] 5f14 6d2 7s2 question-marked

• CRC
  • David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition, online version. CRC Press. Boca Raton, Florida, 2003; Section 1, Basic Constants, Units, and Conversion Factors; Electron Configuration of Neutral Atoms in the Ground State. (elements 1-104)
  • Also subsection Periodic Table of the Elements, (elements 1-103) อ้างต้นฉบับ ได้แก่
    • G. J. Leigh, Editor, Nomenclature of Inorganic Chemistry, Blackwell Scientific Publications, Oxford, 1990.
    • Chemical and Engineering News, 63(5), 27, 1985.
    • Atomic Weights of the Elements, 1999, Pure & Appl. Chem., 73, 667, 2001.

• WebElements
  • http://www.webelements.com/ อ้างต้นฉบับได้แก่
    • Atomic, Molecular, & Optical Physics Handbook, Ed. Gordon W. F. Drake, American Institute of Physics, Woodbury, New York, USA, 1996.
    • J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, HarperCollins, New York, USA, 1993.
    • R.L. DeKock and H.B. Gray in Chemical Structure and bonding, Benjamin/Cummings, Menlo Park, California, USA, 1980.
    • A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.

• • 103 Lr : [Rn].5f14.7s2.7p1 tentative ; 2.8.18.32.32.9.2 [inconsistent]
  • 104 Rf : [Rn].5f14.6d2.7s2 tentative
  • 105 Db : [Rn].5f14.6d3.7s2 (a guess based upon that of tantalum) ; 2.8.18.32.32.11.2
  • 106 Sg : [Rn].5f14.6d4.7s2 (a guess based upon that of tungsten) ; 2.8.18.32.32.12.2
  • 107 Bh : [Rn].5f14.6d5.7s2 (a guess based upon that of rhenium) ; 2.8.18.32.32.13.2
  • 108 Hs : [Rn].5f14.6d6.7s2 (a guess based upon that of osmium) ; 2.8.18.32.32.14.2
  • 109 Mt : [Rn].5f14.6d7.7s2 (a guess based upon that of iridium) ; 2.8.18.32.32.15.2
  • 110 Ds : [Rn].5f14.6d9.7s1 (a guess based upon that of platinum) ; 2.8.18.32.32.17.1
  • 111 Rg : [Rn].5f14.6d10.7s1 (a guess based upon that of gold) ; 2.8.18.32.32.18.1
  • 112 Uub : [Rn].5f14.6d10.7s2 (a guess based upon that of mercury) ; 2.8.18.32.32.18.2
  • 113 Uut : [Rn].5f14.6d10.7s2.7p1 (a guess based upon that of thallium) ; 2.8.18.32.32.18.3
  • 114 Uuq : [Rn].5f14.6d10.7s2.7p2 (a guess based upon that of lead) ; 2.8.18.32.32.18.4
  • 115 Uup : [Rn].5f14.6d10.7s2.7p3 (a guess based upon that of bismuth) ; 2.8.18.32.32.18.5
  • 116 Uuh : [Rn].5f14.6d10.7s2.7p4 (a guess based upon that of polonium) ; 2.8.18.32.32.18.6
  • 117 Uus : [Rn].5f14.6d10.7s2.7p5 (a guess based upon that of astatine) ; 2.8.18.32.32.18.7
  • 118 Uuo : [Rn].5f14.6d10.7s2.7p6 (a guess based upon that of radon) ; 2.8.18.32.32.18.8

• Lange
  • J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), online version, McGraw-Hill, 1999; Section 4, Table 4.1 Electronic Configuration and Properties of the Elements. (Elements 1-103)

• • 97 Bk : [Rn] 5f8 6d 7s2
  • 103 Lr : [Rn] 4f14 [sic] 6d 7s2