Assertion: argon | /r/HasProperty | element number
Facets:
value: on the periodic table
type: LOCATION
Source sentences:
text: Argon, abbreviated Ar, is element number 18 on the periodic table, making it the third-lightest of the six noble gases behind helium (atomic number 2) and neon (number 10).
text: Argon is element number 18 and has the atomic symbol Ar -- renamed in 1959 from its original atomic symbol, which was simply A. As you can see in the image above, argon gas produces a lovely bluish-purple colour when excited with electricity.