This is the 13362nd most frequent Russian word.
наблюдению
"Observation."
The word 'наблюдению' here means 'observation' and is used in the dative case, expressing the state of being under observance.
Эксперимент подлежит тщательному наблюдению.
The experiment is subject to careful observation.
The word 'наблюдению' means 'observation' and is used in the dative case, denoting the instrumental use of observing.
Новые звезды были открыты благодаря тщательному наблюдению.
New stars were discovered thanks to careful observation.
The word 'наблюдения' is related to the process of observing and is used here in the genitive case to specify the type of success in observing.