Target group: studeNts The subjects that chemistry teachers consider having been most difficult for their pupils online were the same subjects that they considered most difficult to teach online. ● Chemistry general ● Mixtures and pure substances ● Solution ● Atoms In Chemistry generally bothAtoms and Molecules were considered difficult to learn online for the students. In Mixtures and Pure substances, the topic Methods of separating pure substances from mixtures is reported as the most challenging in online learning followed by the topic Distinction between pure substances and mixtures. Regarding Solutions, the most difficult topics in learning online were Concept of solubility of substances and saturation of solutions and Solutions as examples of mixtures and distinction between solvent and solute. Finally, in Atoms, the topic Ions was absolutely the most difficult topic for the students to learn online. Physic Target group: teachers For Physics, the most difficult subjects in teaching online were: ● Accelerated motion and Newton’s second law ● Forces ● Density, pressure and buoyancy 20