TO SUM UP
Matter anything that has mass and occupies space is divided into two categories-pure substances and mixtures.
Elements are the simplest type of pure substance and are represented by symbols.
A compound is made up of two or more elements chemically bonded together and is shown by a formula.
Mixtures are composed of two or more substances combined in varying amounts.
Atoms are the smallest particle of an element the keep the chemical properties of the element.
Chemical bonds between atoms can be either ionic or covalent, depending on whether electrons are transferred or shared.
A chemical change is a process where substances become new and different substances.
Physical changes in a substance involve changes such as size. shape, or phase, but the basic identity of the substance does not change