Assertion: tin's form | /r/HasProperty | white tin
Facets:
value: from 18°c
type: TEMPORAL
Source sentences:
text: At temperatures above 13.2°C, gray tin slowly turns into tin's second form, white tin.
text: The normal form is white tin, or beta tin, which has a body-centred tetragonal crystal structure.
text: Pure crystalline tin exists in two allotropic modifications, the metallic form (white tin), and a semimetallic form (grey tin).
text: From 18°C to 161°C, the stable form is β-tin, or white tin, a metal of tetragonal crystal structure and a density of 7.2984.