Toolchest · Datasheet

Accumath Periodic Table Dataset — Notes

Dataset: accumath-periodic-table.csv — 118 elements, 24 columns. Compiled 2026-10-20 for the planned Accumath Toolchest section. Rule applied throughout: every value was transcribed from a page actually opened during the research session. Anything not verifiable from an opened source was left EMPTY — never estimated, never interpolated. Values that appear in reference compilations only as predictions (usually parenthesised) were excluded and are listed under Gaps.

Sources used (per-row detail is in the CSV sources column)

Source	What it supplied
CIAAW Table 1, in Coplen et al., "The Table of Standard Atomic Weights — An exercise in consensus" (PMC9286417). The article states Table 1 agrees with the CIAAW TSAW published 2022 (= CIAAW 2021), the same weights NIST publishes.	atomic_mass_u for the 84 elements that have a standard atomic weight
NIST SP 966 (NIST periodic table PDF, June 2019)	electron_configuration (Z 1–109), bracketed mass numbers for elements with no standard atomic weight, ionization energies (cross-check / primary)
NIST ASD (Atomic Spectra Database) values as captured in session	ionization energy spot values; agrees with SP 966 / CRC to 4–6 digits where compared
CRC Handbook of Chemistry and Physics, 105th ed. (2024–25), Table 2.5 "Properties of the Elements", as reproduced by Nucleonica (wiki Part4.pdf). Gas densities in that table are from the CRC 95th ed.	density, melting point, boiling point, ionization energy (cross-check)
Wikipedia, "List of chemical elements"	group, period, block, electronegativity (Pauling), specific heat capacity, phase at standard state; fallback boiling points for Ra, Pa, Cm, Bk and density for Es where CRC is silent and the List value is not a prediction
Wikipedia, "Atomic radius" — empirical atomic radii of J. C. Slater (1964)	atomic_radius_pm
Wikipedia, "Electron affinity" (periodic table of electron affinities, kJ/mol)	electron_affinity_eV (converted, see below)
Wikipedia, "Oxidation state" (table of oxidation states of the elements)	oxidation_states (main/bold states)
NIST Chemistry WebBook (NIST Standard Reference Database 69), element species pages — added in the 2026-10-20 follow-up pass	CAS_number for 110 elements, exactly as printed ("CAS Registry Number")
EnvironmentalChemistry.com, "Periodic Table of Elements — Sorted by Thermal Conductivity" (Kenneth Barbalace; page last updated 2007-02-22) — added in the 2026-10-20 follow-up pass	thermal_conductivity_W_mK for 105 elements (published in W/cm·K, converted ×100 — see Basis notes)

Deviation from the original sourcing plan

The Royal Society of Chemistry periodic table could not be used as a batch source: the RSC table root is a JavaScript application exposing no data, and no RSC per-element page was ever returned by a search result in a form that could be opened. Rather than guess URLs, the physical-property columns were built from the CRC Handbook table (an approved source in the task) with the Wikipedia List as the second source — which also made a genuine two-source cross-check possible. The Los Alamos periodic table is per-element only and was not batch-accessible either.

Basis notes

• Atomic masses. CIAAW standard atomic weights. For the 14 elements whose standard atomic weight is an interval (H, Li, B, C, N, O, Mg, Si, S, Cl, Ar, Br, Tl, Pb), the CSV shows the CIAAW conventional value and the row note gives the interval. For the 34 elements with no standard atomic weight (Tc, Pm, Po, At, Rn, Fr, Ra, Ac, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og), atomic_mass_u shows the bracketed mass number of the longest-lived isotope (NIST SP 966) or most stable isotope (Wikipedia List), e.g. [98]. Bi, Th, Pa, U have no stable isotope but do have tabulated standard atomic weights (208.98040, 232.0377, 231.03588, 238.02891) and are shown unbracketed.
• Density. CRC basis: solids/liquids at 25 °C; the gas values in CRC are in g/L (CRC 95th ed.) and were converted to g/cm³ (÷1000) — they correspond to ~25 °C, which is why they sit ~9 % below the Wikipedia List gas densities (quoted near 0 °C). Where an element has allotropes, the form stable at 25 °C is used and the row note says so (graphite C 2.2, white P 1.823, rhombic S 2.07, gray Se 4.809, white Sn 7.287, β-Bk 13.25). Os and Ir densities are quoted at 20 °C in CRC.
• Melting/boiling points. CRC publishes °C; converted to K (+273.15). Carbon's "melting point" (4762.15 K) is its triple point at 10.3 MPa — carbon sublimes at 1 atm (sublimation point 4098.15 K), so boiling_point_K is empty. Arsenic's melting point (1090.15 K) is its triple point at 3700 kPa; it too sublimes at 1 atm (889.15 K), so its boiling point is empty. Boiling points CRC flags with "~" (Ba, Pm, Ac, Np, Am) are flagged as approximate in the row notes.
• Ionization energy. First IE, NIST-first (SP 966 / ASD). CRC's IE column reproduces the same NIST data and agrees to 4–6 significant digits almost everywhere; it was used as the cross-check, not the source (one exception in reverse: see Ac under Discrepancies).
• Electron affinity. The opened source table gives kJ/mol, rounded to the nearest kJ/mol; converted with 1 eV = 96.485 kJ/mol and rounded to 3 decimals (±~0.005 eV). Only measured values are included — entries the source shows in parentheses are predictions and were excluded (this removes e.g. all noble gases, Be, Mg, Mn, Zn, Cd, Hg, Tc, Po, and all period-7 elements except Th and U among the actinides). Sign convention: positive = energy released on electron attachment (the IUPAC Eea convention used by the source); N (−0.073) and Yb (−0.021) are negative.
• Molar heat capacity. Derived: (specific heat capacity in J/g·K from the Wikipedia List) × (atomic mass in g/mol; the bracketed mass number for Rn, Ra, Ac). This is a unit conversion of sourced values, not new data.
• Electrons per shell. Derived by expanding the NIST SP 966 noble-gas-shorthand configuration; the build script asserted the shell counts sum to Z for all 109 configured elements, and they do.
• Electron configurations. NIST SP 966 noble-gas shorthand. SP 966 prints no configurations for Z ≥ 110 (Ds–Og), so those cells are empty rather than filled with the predicted configurations that circulate elsewhere.
• Oxidation states. The main (bold) states from the Wikipedia "Oxidation state" table — i.e. the common states, not the exhaustive list including exotic ones. Where the table lists states but bolds none (Rn, Db, Sg, Bh, Hs, Cn), the listed states are shown.
• Category. RSC-style classification: lanthanide = La–Lu (57–71), actinide = Ac–Lr (89–103); Lu and Lr therefore sit in group 3 / d-block for group/block but carry the lanthanide/actinide category. Po is classed post-transition metal. Group is blank for f-block elements other than Lu/Lr (the List's "f-block groups"). Og is classed noble gas and Ts halogen by position (predicted).
• Standard state. Phase at 25 °C / 100 kPa per the Wikipedia List. Elements the List shows as "unknown phase" (At, Fr, Fm, Md, No, Lr, Rf and Z 105–118) are left empty even though several are predicted solids.
• CAS numbers (follow-up pass, 2026-10-20). Recorded exactly as printed in the "CAS Registry Number" field of the NIST Chemistry WebBook species page for each element. For elements whose standard state is diatomic, the molecular species page was used (H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂ — e.g. hydrogen is the WebBook's H₂ entry, 1333-74-0). Two WebBook quirks: astatine's only page is titled "Astatine, atomic" (142364-73-6), and the tellurium formula search returns two species both named "Tellurium" — the elemental record carrying the phase-change data (13494-80-9) is used; the second record carries 22541-49-7. The WebBook has no species at all for Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og (formula search returns "no species found"), so those eight cells stay empty.
• Thermal conductivity (follow-up pass, 2026-10-20). Single source: EnvironmentalChemistry.com's openly published sorted-by-thermal-conductivity table (Barbalace). The table prints W/cm·K; values were converted to W/m·K (×100) — a unit conversion of the published figures, not new data. The source states no measurement temperature; the figures are the conventional room-temperature values for the pure element in its standard state and agree with other published compilations where spot-compared. Two transparency flags: (1) for Am–Lr the table prints a uniform 10, and for Rf 23 / Db 58 — elements never produced in bulk; these are the compilation's nominal published values, transcribed as published, and are not measurements; (2) tellurium — see Discrepancies #14. The table lists nothing for Sg, Bh, Hs, Mt, Ds, Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og, so those 13 cells stay empty.

Legal basis (per Jeff's constraint, 2026-10-20)

• NIST family (public domain). NIST Physical Reference Data, SP 966, ASD and the CIAAW weights as published by NIST are US-government material — public domain. These cover atomic masses, configurations, ionization energies, and (via the bracketed mass numbers) the no-stable-isotope elements. Safe for commercial use.
• CRC Handbook (copyrighted compilation — facts only). Density, melting and boiling points are elemental facts recorded with the CRC Handbook named as the source; no CRC text, table layout, or presentation was copied. Facts as such are not copyrightable expression, but the compilation is commercial: if a fully public-domain chain of title is ever required for these three columns, they are the columns to re-base on a US-government source (e.g. a Los Alamos National Lab pass). Flagged here rather than silently relied on.
• Wikipedia-derived data (CC BY-SA, facts only, attribution given). Group / period / block, Pauling electronegativities, specific heats, phases, Slater radii, electron affinities and oxidation states are facts recorded with the source named in every row's sources column; no article text was copied. The underlying compilations are themselves standard references (Pauling electronegativities; Slater, J. Chem. Phys. 1964).
• CAS numbers and thermal conductivity (filled in the 2026-10-20 follow-up pass — published facts, no license required). Per Jeff's ruling of 2026-10-20, publicly published facts are public and do not require licensure (facts are not copyrightable — Feist v. Rural Telephone, 1991). Both columns shipped empty in the first pass out of caution and were filled once the ruling was given:
• CAS_number — the numbers as printed by the NIST Chemistry WebBook, a US-government (public-domain) publication, with NIST named as the source in every filled row. The numbers are identifiers/facts; nothing was taken from the CAS registry itself and no ACS/CAS text was copied. 110 of 118 filled; the 8 blanks are elements the WebBook has no species for (see Gaps).
• thermal_conductivity_W_mK — numbers only, from the openly published EnvironmentalChemistry.com compilation (Barbalace), named as the source in the sources table above and in every filled row; no text, table layout, or presentation was copied. 105 of 118 filled; the 13 blanks are elements the table does not list (see Gaps).

Cross-check (10 elements, NIST-family vs CRC vs Wikipedia List)

El	Mass (CIAAW vs List)	Ionization energy (NIST vs CRC)	Density / mp / bp (CRC vs List)
H	1.008 = 1.0080 ✓	13.5984 vs 13.598443 ✓	density 0.000082 vs 0.00008988 — temperature basis (≈25 °C vs ≈0 °C), see Basis notes; mp 13.99 vs 14.01 K; bp 20.27 vs 20.28 ✓
C	12.011 ✓	11.2603 vs 11.26030 ✓	graphite density 2.2 vs 2.267 (graphite density is a range); mp: CRC triple point 4762 K vs List ">4000"
Na	22.98976928 vs 22.990 (abridged) ✓	5.1391 vs 5.139076 ✓	0.97 vs 0.968 ✓; mp 370.93 vs 370.87; bp 1156.09 vs 1156 ✓
Al	26.9815384 vs 26.982 ✓	5.9858 vs 5.985768 ✓	2.70 ✓; mp 933.47 ✓ both; bp 2792.15 vs 2792 ✓
S	32.06 ✓	10.3600 vs 10.36001 ✓	rhombic 2.07 ✓ both; mp 388.36 ✓ both; bp 717.76 vs 717.87
Fe	55.845 ✓	7.9025 vs 7.9024 ✓	7.87 vs 7.874 (rounding); mp 1811.15 vs 1811 ✓; bp 3134.15 vs 3134 ✓
Cu	63.546 ✓	7.7264 vs 7.72638 ✓	8.96 ✓; mp 1357.77 ✓ both; bp 2833.15 vs 2835
Ag	107.8682 vs 107.87 ✓	7.5762 vs 7.57623 ✓	10.5 vs 10.49 ✓; mp 1234.93 ✓ both; bp 2435.15 vs 2435 ✓
Au	196.966570 vs 196.97 ✓	9.2256 vs 9.22553 ✓	19.3 ✓; mp 1337.33 ✓ both; bp 3109.15 vs 3129 (Δ20 K, see below)
U	238.02891 vs 238.03 ✓	6.1941 ✓ both	19.1 ✓; mp 1408.15 vs 1405.3; bp 4404.15 vs 4404 ✓

Discrepancies found (beyond the sample)

1. Actinium ionization energy: CRC Table 2.5 prints 5.17 eV; NIST (SP 966 / ASD) gives 5.3802 eV. The NIST value is used; CRC's appears to be a stale value.
2. Technetium mass number: NIST SP 966 gives (98) (longest-lived isotope); Wikipedia List gives [97]. CSV uses [98] with a row note.
3. Superheavy bracketed masses: NIST SP 966 vs Wikipedia List disagree for Sg ((269) vs [267]), Hs ((269) vs [271]) and Mc ((289) vs [290]). The List values are used (SP 966's period-7 mass tokens were visibly scrambled in the PDF) and each row carries a note.
4. Argon mass: CIAAW 2021 conventional value is 39.95; NIST SP 966 (2019) prints 39.948 — SP 966 predates the CIAAW revision. CIAAW value used.
5. Ruthenium density: CRC 12.1 vs List 12.45 g/cm³. CRC value used.
6. Selenium melting point: CRC 493.95 K (220.8 °C) vs List 453 K. CRC used; the List figure does not match the accepted 221 °C melting point.
7. Lithium / gallium / tungsten boiling points: CRC vs List differ materially (Li 1617.25 vs 1560 K; Ga 2502.15 vs 2673 K; W 5828.15 vs 6203 K). CRC used in all three cases.
8. Thorium melting point: CRC 2023.15 K (1750 °C) vs List 2115 K. CRC used.
9. Americium boiling point: CRC prints ≈2011 °C (its own estimate flag) → 2284.15 K; the List gives 2880 K. CRC retained as primary source, flagged in the row note as an estimate in the source.
10. Francium: CRC mp/bp 300.15 K / 936.15 K vs List 281 K / 890 K. CRC used.
11. Gold boiling point: CRC 3109.15 K vs List 3129 K (from the sample table).
12. Minor (≤ ~5 K or last-digit) mp/bp differences between CRC and the List for K, Ti, Sr, Y, Zr, Nb, Ho, Np, In, Sn, Cs, Ba, Ce, Pr, Nd, Eu, Tb, Dy, Lu, Au, Hg, U — CRC used throughout; individually immaterial.
13. Ionization-energy rounding differences between NIST SP 966 and CRC at the 4th–5th digit (Pr 5.4702 vs 5.473; Pu 6.0258 vs 6.0260; Np 6.2655 vs 6.2657; Bk 6.1978 vs 6.1979; Es 6.3676 vs 6.42; Lr 4.96 vs 4.9). NIST values used.
14. Tellurium thermal conductivity (follow-up pass): the primary source (EnvironmentalChemistry.com) publishes a single value, 0.0235 W/cm·K → 2.35 W/m·K, which is used. Other published tables (e.g. the Wikipedia element infobox) give a range, 1.97–3.38 W/(m·K), because crystalline tellurium is anisotropic. The single published value is retained per the one-value-per-element rule; the range is recorded here so the simplification is not silent.

Gaps (empty cells, by column)

• CAS_number — empty for 8 elements: Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og. The NIST Chemistry WebBook has no species for these elements, so no NIST-printed CAS number exists to record. (Filled for the other 110 in the follow-up pass.)
• thermal_conductivity_W_mK — empty for 13 elements: Sg, Bh, Hs, Mt, Ds, Rg, Cn, Nh, Fl, Mc, Lv, Ts, Og — not listed in the published source table. (Filled for the other 105 in the follow-up pass.)
• electron_configuration / electrons_per_shell — empty for Z 110–118 (Ds–Og): NIST SP 966 prints no configurations there; predicted ones were excluded.
• ionization_energy_eV — empty for Z 105–118 (Db–Og): NIST SP 966 prints only ambiguous estimates for a few of these; none were recorded.
• density_g_cm3 — empty for At, Fr, Fm, Md, No, Lr, Rf and Z 105–118 (CRC gives none; the List's figures for these are parenthesised predictions, excluded).
• melting_point_K — empty for He (does not solidify at 1 atm), Rf, and Z 105–118.
• boiling_point_K — empty for C and As (sublime at 1 atm; see Basis notes), At, Cf, Es, Fm, Md, No, Lr, Rf, and Z 105–118. (List values in parentheses for Cf/Es boiling points are predictions and were excluded; unparenthesised List values were used for Ra, Pa, Cm, Bk.)
• electron_affinity_eV — empty for 44 elements whose source-table entries are predictions (parenthesised) or absent: He, Be, Ne, Mg, Ar, Mn, Zn, Kr, Tc, Cd, Xe, Hg, Po, Rn, Fr, Ra, Ac, Pa, and every element from Np (93) to Og (118). (Measured values exist for 74 elements, including Th and U among the actinides.)
• atomic_radius_pm — empty where Slater (1964) gives no value: He, Ne, Ar, Kr, Xe, At, Rn, Fr, Cm (two reproductions of Slater's table conflict — one shows 175 pm, two others show "no data" — so it was left empty), Bk–Lr, and Z 104–118.
• electronegativity_Pauling — empty for He, Ne, Ar (not defined on the Pauling scale), Fr (List gives only a predicted bound, >0.79), and Z 104–118. Note: the List's values for Kr (3.00), Xe (2.60), Rn (2.2) and the late actinides (1.3) extend beyond Pauling's original assignments; they are recorded as published.
• oxidation_states — empty for He (no states listed) and Mt, Ds, Rg, Nh, Fl, Mc, Lv, Ts, Og (no states listed in the source table).
• standard_state — empty for the 21 elements the List shows as "unknown phase".
• molar_heat_capacity_J_molK — empty where the List gives no specific heat (Tc, Pm, Po, At, Fr, Pa, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Z 105–118).
• group — blank for La–Yb and Ac–No by the f-block convention described above (not missing data).

Coverage summary

118 rows. Filled cells per column: atomic mass 118 (84 CIAAW weights + 34 bracketed mass numbers), category/group/period/block 118/90/118/118, configuration 109, density 97, melting point 102, boiling point 94, electronegativity 99, atomic radius 87, ionization energy 104, electron affinity 74, oxidation states 108, standard state 97, molar heat capacity 86, thermal conductivity 105, CAS number 110.