Usually parameters reproduce the value, and the template adds the SI unit or additional standard text. While the topic is technical, we can strive to make the result readable text, and even verbose. For example, this is why the template writes "(at 0 °C)". For this, you may want to experiment with parameter input too - or propose improvements.
All this can vary across the values (data rows). So depending on the row and the specific value, additional formattings may be added by the template (e.g., a newline <br/>)
Most parameters have a ... ref that allows for references. This reference is added right after the unit.
ionization energy ref
Parameters with a .. comment suffix are added to the end of a data line, with a space added. Comments are reproduced without formatting additions (no brackets, no italics, ...):
{{Infobox element|name=|symbol=|number=<!-- image -->|image name=|image upright=|spectral image=<!-- central data list --><!-- General properties -->|pronounce=<!-- central data list -->|alt name=|alt names=|allotropes=|appearance=|standard atomic weight=<!-- central data list --><!-- Periodic table -->|above=|below=|left=|right=|category ref=|category comment=|category color=|group=|group ref=|group comment=|period=|period ref=|period comment=|block=|block ref=|block comment=|electron configuration=|electron configuration ref=|electron configuration comment=|electrons per shell=|electrons per shell ref=|electrons per shell comment=<!-- Physical properties -->|physical properties comment=|color=|phase=|phase ref=|phase comment=|melting point K=|melting point C=|melting point F=|melting point ref=|melting point comment=|boiling point K=|boiling point C=|boiling point F=|boiling point ref=|boiling point comment=|sublimation point K=|sublimation point C=|sublimation point F=|sublimation point ref=|sublimation point comment=|density gplstp=|density gplstp ref=|density gplstp comment=|density kgpm3stp=|density kgpm3stp ref=|density kgpm3stp comment=|density gpcm3nrt=|density gpcm3nrt ref=|density gpcm3nrt comment=|density gpcm3nrt 2=|density gpcm3nrt 2 ref=|density gpcm3nrt 2 comment=|density gpcm3nrt 3=|density gpcm3nrt 3 ref=|density gpcm3nrt 3 comment=|density gpcm3mp=|density gpcm3mp ref=|density gpcm3mp comment=|density gpcm3bp=|density gpcm3bp ref=|density gpcm3bp comment=|molar volume=|molar volume unit =|molar volume ref=|molar volume comment=|triple point K=|triple point kPa=|triple point ref=|triple point comment=|triple point K 2=|triple point kPa 2=|triple point 2 ref=|triple point 2 comment=|critical point K=|critical point MPa=|critical point ref=|critical point comment=|heat fusion=|heat fusion ref=|heat fusion comment=|heat fusion 2=|heat fusion 2 ref=|heat fusion 2 comment=|heat vaporization=|heat vaporization ref=|heat vaporization comment=|heat capacity=|heat capacity ref=|heat capacity comment=|heat capacity 2=|heat capacity 2 ref=|heat capacity 2 comment=|vapor pressure 1=|vapor pressure 10=|vapor pressure 100=|vapor pressure 1 k=|vapor pressure 10 k=|vapor pressure 100 k=|vapor pressure ref=|vapor pressure comment=|vapor pressure 1 2=|vapor pressure 10 2=|vapor pressure 100 2=|vapor pressure 1 k 2=|vapor pressure 10 k 2=|vapor pressure 100 k 2=|vapor pressure 2 ref=|vapor pressure 2 comment=<!-- Atomic properties -->|atomic properties comment=|electronegativity=|electronegativity ref=|electronegativity comment=|ionization energy 1=|ionization energy 1 ref=|ionization energy 1 comment=|ionization energy 2=|ionization energy 2 ref=|ionization energy 2 comment=|ionization energy 3=|ionization energy 3 ref=|ionization energy 3 comment=|number of ionization energies=|ionization energy ref=|ionization energy comment=|atomic radius=|atomic radius ref=|atomic radius comment=|atomic radius calculated=|atomic radius calculated ref=|atomic radius calculated comment=|covalent radius=|covalent radius ref=|covalent radius comment=|Van der Waals radius=|Van der Waals radius ref=|Van der Waals radius comment=<!-- Miscellanea -->|crystal structure=|crystal structure prefix=|crystal structure ref=|crystal structure comment=|crystal structure 2=|crystal structure 2 prefix=|crystal structure 2 ref=|crystal structure 2 comment=|speed of sound=|speed of sound ref=|speed of sound comment=|speed of sound rod at 20=|speed of sound rod at 20 ref=|speed of sound rod at 20 comment=|speed of sound rod at r.t.=|speed of sound rod at r.t. ref=|speed of sound rod at r.t. comment=|thermal expansion=|thermal expansion ref=|thermal expansion comment=|thermal expansion at 25=|thermal expansion at 25 ref=|thermal expansion at 25 comment=|thermal conductivity=|thermal conductivity ref=|thermal conductivity comment=|thermal conductivity 2=|thermal conductivity 2 ref=|thermal conductivity 2 comment=|thermal diffusivity=|thermal diffusivity ref=|thermal diffusivity comment=|electrical resistivity=|electrical resistivity unit prefix=|electrical resistivity ref=|electrical resistivity comment=|electrical resistivity at 0=|electrical resistivity at 0 ref=|electrical resistivity at 0 comment=|electrical resistivity at 20=|electrical resistivity at 20 ref=|electrical resistivity at 20 comment=|band gap=|band gap ref=|band gap comment=|Curie point K=|Curie point ref=|Curie point comment=|magnetic ordering=|magnetic ordering ref=|magnetic ordering comment=|tensile strength=|tensile strength ref=|tensile strength comment=|Young's modulus=|Young's modulus ref=|Young's modulus comment=|Shear modulus=|Shear modulus ref=|Shear modulus comment=|Bulk modulus=|Bulk modulus ref=|Bulk modulus comment=|Poisson ratio=|Poisson ratio ref=|Poisson ratio comment=|Mohs hardness=|Mohs hardness ref=|Mohs hardness comment=|Mohs hardness 2=|Mohs hardness 2 ref=|Mohs hardness 2 comment=|Vickers hardness=|Vickers hardness ref=|Vickers hardness comment=|Brinell hardness=|Brinell hardness ref=|Brinell hardness comment=|CAS number=|CAS number ref=|CAS number comment=<!-- History -->|naming=|predicted by=|prediction date ref=|prediction date=|discovered by=|discovery date ref=|discovery date=|first isolation by=|first isolation date ref=|first isolation date=|discovery and first isolation by=|named by=|named date ref=|named date=|history comment label=|history comment=<!-- Isotopes not here --><!-- other -->|engvar=|QID=}}
As of 7 Jan 2023[update], the "Main isotopes of <element>" tabular list will be read directly from the Isobox: "Infobox <element> isotopes". For example, {{Infobox uranium}} will read the table live from {{Infobox uranium isotopes}}.
The headerbar provides View-Edit links to that Isobox.
Theoretical elements handling (E119) [change source]
As of 1 Jan 2023[update], elements E119 and higher are not discovered. These are called theoretical elements. They can have article and other content pages though. Incidentally, this concerns period 8 completely. For the Infobox <element>, their redirected pages do not count (are treated as: "R page does not exist").
Possible situations regarding articles & discovery, are:
"E118": E1–E118, discovered, existing full set, mentioned here for easy reference
"E127, E185": E123, E125, E127 ...Unbitrium Redirect: no article, no other content pages.
Creation of pages is governed by MOS:NONEWELEMENTS. This infobox must distinguish between three typical (exemplary) elements: E118 (regular element), E119 and E121.
Handling of these element infoboxes is hardcoded in the meta-infobox, set by |number= (Z).
Theoretical element: above-header shows
Theoretical element
Applied: when element is theoretical (E119 and higher).
No article "Isotopes of <element>": Header does not link
As of 4 Jan 2023[update], conforms MOS:no new elements (no idle pages created; redirects for element names only)
Uue–Uoq (E119–E184) each have an article page by their systematic name. That is 66 article page. Six of these are content pages (articles), and 58 are a redirect.
R: Redirects are non-content pages. Treated as non-existant page.
E172 would be the end of period 8 ("noble gas") and E173 would be the beginning of period 9.
All element articles and their infoboxes use IUPAC spelling of elements and compounds. Notably, that is aluminium, sulfur, caesium, not aluminum, sulphur, cesium. For other English variant words (vapor vs. vapour) the infobox reads |engvar=. The parameter should be set in the article, and has options: en-US (or blank; default), en-GB, en-OED.
Wikidata