The results of the implementation of formative assessment into chemistry education at secondary school for the topic "Mixtures" are presented here. Students (12-14 years old, N=202) were divided into two groups--control (N=97) and experimental (N=105). Teachers of experimental group implemented formative assessment tools into ten lessons (a predictive card, Frayer model, self-assessment card, T-card, concept map, and exit card). Control group teachers taught without formative assessment. The Mann-Whitney U test confirmed statistically significant results (p<0.05). [For the full proceedings, see ED619611.]