Μαθητής κοιτάζοντας το ίζημα σε φιάλη και γράφοντας αποτελέσματα, μάθημα χημείας - Φωτογραφίες & Εικόνες Αρχείου

Boy in protective glasses mixing chemical liquids in flasks, curious genius

Little chemist in protective glasses checking reaction in tube with green liquid

Schoolboy watching reaction in tube with green liquid, chemistry lessons

Schoolboy looking at red liquid in flask and scratching head, having no idea

Boy in protective gloves and glasses writing down chemical experiments results

Clever schoolboy adding drops of agent into tube with green reagent, chemistry

Laboratory worker writing down chemical research results, conducting experiments

Chemistry scientist conducting researches in office, holding flasks with liquids

Female scientist comparing flasks with colored liquid, detergent laboratory

Woman scientist holding pipette with liquid and taking test tube with reagent

Chemistry experimenter writing down results of scientific researches in lab

Female scientist in laboratory looking to camera, equipment standing on table