1. Definition of chemistry Chemistry is the study of the nature, properties, and composition of matter, and how these undergo changes

2. matter Definition of matter is often said that matter is anything which has mass and occupies space

3. Properties of matter Properties of matter can be classed as either physical or chemical or mechanical.. Physical properties include boiling point, melting point, thermal (heat) conductivity, color, viscosity, reflectivity, hardness, color, taste and smell.

4. A chemical property, on the other hand, describes a chemical change: the interaction of one substance with another, or the change of one substance into another. Mechanical properties as speed, mass, strength and weight

5. Dalton's atomic theory

6. The atoms of a given element are similar to each other but different from those of any other element. All atoms of a given element are identical. element Atoms of one element can combine with atoms of other elements to form chemical compounds; a given compound always has the same relativechemical compounds

7. Elements are made of tiny particles called atoms. atoms