Question: What are the chemical element  which start with the letter y
Paraphrase: What are the chemical component which begin with the letter y
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q11344 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'y')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: ytterbium, ytterbium, yttrium, yttrium