“The Effect of Using the (Harwood) model on Achievement of the First-Grade Intermediate Students in Chemistry and their Cognitive Flexibility”. Journal of the College of Basic Education, [S. l.], v. 32, n. 138, p. 240–258, 2026. DOI: 10.35950/cbej.v32i138.16052. Disponível em: https://cbej.uomustansiriyah.edu.iq/index.php/cbej/article/view/16052.. Acesso em: 1 nov. 2026.