Assertion: cesium | /r/HasProperty | spelled caesium
Facets:
value: sometimes
type: TEMPORAL
Source sentences:
text: Cesium (sometimes spelled ‘caesium’) was discovered by Robert Bunsen and Gustav Kirchhoff in 1860.
text: Cesium (pronounced as SEE-zee-em), sometimes spelled as caesium, is a highly reactive metal when exposed to air and water.