Final answer:
Elements are simplest and found on the periodic table, compounds are made of two or more elements chemically bonded, and mixtures combine substances physically. Substances are further classified based on composition into atomic elements, molecular elements, compounds (molecular or ionic), and mixtures (homogeneous or heterogeneous).
Step-by-step explanation:
To correctly sequence elements, compounds, and mixtures in terms of increasing complexity, we start with elements which are the simplest form of matter found on the periodic table. Compounds come next, as they are made up of two or more different elements in a fixed ratio that are chemically bonded. Mixtures are the most complex, comprising two or more substances (elements or compounds) that are combined physically but not chemically, and can be further classified into homogeneous (uniform composition) and heterogeneous (non-uniform composition).
Classifying substances can be done by building models using colored balls. This visual representation helps differentiate between atomic elements, molecular elements, molecular compounds, ionic compounds, and various types of mixtures, whether they're pure or impure substances.
For instance, substances like gold (atomic element), oxygen (molecular element), carbon dioxide (molecular compound), and salt (ionic compound) can be distinguished. Mixtures like soil would be considered a heterogeneous mixture, while a solution like salt water is a homogeneous mixture.
In an exercise to classify different substances, salt would be an ionic compound, pure water a molecular compound, soil a heterogeneous mixture, salt water a homogeneous mixture, pure air a homogeneous mixture, carbon dioxide a molecular compound, gold an element (atomic), and bronze a heterogeneous mixture.