A review of matter started the class, the definition of matter, mass, and volume. Chemistry was defined as the study of matter. Chemists would be interested in the makeup and reactions of matter. Using common salt, the question of whether salt water, table salt or mined salt would be different. It was determined that there was no difference in the salt, the chemical formula being the same. The definition of a substance was derived. Examples of copper, iron, magnesium, zinc, and carbon were demonstrated to show that no matter how small the chemical was "cut", the resulting product was the same as the original.This was defined as an element, and the definition of an element was written. The final "cut of the element" would result in an atom. The atom was defined as the basic particle of which all elements are composed. The properties of different elements were related to the different atoms.