About: http://webisa.webdatacommons.org/75127899

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	They are made from lighter materials such as hydrogen, helium, water, ammonia, and methane.
http://www.w3.org/ns/prov#wasQuotedFrom	ck12.org