Whenever Science is taught in schools, it is always a simplified model. At Primary school, the model is extremely simple. At older ages it is more complex, but still misses out key ideas. Even at the very ends of scientific understanding, the best scientists can do is create extremely accurate models.

Take the atom, for example, as you go from elementary school to the very hight levels.

A ball of matter ------> Negative electrons orbiting a positive nucleus---> a nucleus made of quarks bonded by the strong force, surrounded by electrons in shells and sub-shells, moving unpredictable as dictated by quantum mechanics, to form a 'cloud' of probabilities.