Schoolboy dodając płyn do probówki z zieloną substancją, obserwując reakcję - Materiał filmowy & wideo

Little schoolboy checking test tube with violet liquid at chemistry lesson

Female chemist with tablet computer checking test tubes in laboratory

Male pupil mixing liquids in flasks on chemistry lesson, observing reaction

Chemical experiments for children. Fun experiments for children. A woman conducts cognitive science lessons. Drop of dye from the pipette falls into a flask of clear water. Preparation of liquid for

Little schoolboy checking test tube with violet liquid at chemistry lesson

Male pupil mixing liquids in flasks on chemistry lesson, observing reaction

Teacher helping little schoolboy with chemistry experiment, laboratory work

Little scientist comparing flasks with blue and red liquids, experiment result

Biologist adding nitrogen in tubes with green plants, preservation experiment

Chemist checking sediment in tube with yellow liquid, substances emitting smoke