To understand the relationship between macroscopic observations and what happens on the atomic level, concepts are explained using models. Students are challenged to create their own models to deepen ...

He suggested that an atom was a tiny solid ball. He published his ideas in 1803. This atomic model has changed over time. Scientists used the model to make predictions. Sometimes the results of ...

In the modern periodic table, elements are in order of atomic number in periods and groups. Electronic structures model how electrons are arranged in atoms. Groups in the periodic table - AQA ...