不純 ふじゅん分子 ぶんしじゃありませんでした
fujumbunshijārimasendeshita

Noun
Desu Copula

The polite, past negative form of 不純分子

1. Was not an undesirable element.; Was not an impure element.; Was not a troublemaker.

Past/Perfective
Negative
Polite
Terminal Form