This is the 10821st most frequent French word.
observant
Paying careful attention; watchful.
Here, 'observante' is used as an adjective to describe a person's quality of being watchful and noticing fine details.
Elle est très observante et remarque les moindres détails.
She is very observant and notices the tiniest details.
In this sentence, 'observants' is an adjective describing the students' required behavior of attentiveness and careful watching.
Les élèves doivent être observants pendant les démonstrations en laboratoire.
Students must be observant during laboratory demonstrations.
The word 'observent' here is a verb (third person plural form of 'observer'), illustrating the act of actively watching or studying an object or scene.