酸素 さんそ ぞく元素 げんそではありませんでした
sansozoku gensodewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 酸素族元素

1. Was not a chalcogen.; Was not an oxygen group element.

Past/Perfective
Negative
Polite
Formal Register
Chemistry