what is the {follows} for {deuterium} has {instance of} as {isotope of hydrogen} ?
When is deuterium the isotope of hydrogen?
SELECT ?value WHERE { wd:Q102296 p:P31 ?s . ?s ps:P31 wd:Q466603 . ?s pq:P155 ?value}
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q102296> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P31> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q466603> .
?statement <http://www.wikidata.org/entity/P155> ?value. 
} 

At what point is the isotope of hydrogen deuterium?