1. Chemistry1: The Science of Matter Matter takes up space and has mass Mass is the amount of matter Properties of matter describe the characteristics and behavior of matter Matter can be viewed as macroscopic or microscopic Models connect the macroscopic and microscopic views

2. Classifying Matter Matter can be classified by composition: both qualitative and quantitative Matter can be divided into pure substance or mixture For pure substance, it is either element or compound For mixture, it is either homogeneous or heterogeneous Mixtures can be separated by physical means

3. Physical and chemical changes Physical changes can separate mixtures into pure substances Chemical changes involve combining atoms to form new compounds, usually heat is required Elements are basic building blocks of compounds All elements have been organized in the periodic table

4. Compounds All compounds consist more than one element A formula is a combination of chemical symbols that show what elements make up a compound and the number of atoms of each element

5. Properties and changes of matter There are 4 states of matter: solid, liquid, gas, and plasma Density is the mass contained in a unit of volume Solids are denser than liquids because the molecules are closer together Chemical changes can be endothermic or exothermic

6. Chemical Symbols Each element is represented by a chemical symbol—consists of up to 2 letters—the 1 st letter is always capitalized; the 2 nd is always lower case. Some have Latin names, such as Na, K, Sb, Cu, Au, Ag, Fe, Pb, Hg, Sn, W, etc.

7. Energy Energy is the capacity for doing work Stored chemical energy is a form of potential energy, the energy of position When a substance is burned, it is converted into kinetic energy, the energy of motion Heat energy can be transferred from one body to another because of a temperature difference

8. Conservation of Energy The law of conservation of energy states that in any chemical or physical process, energy is neither created nor destroyed.

9. Chemical Reactions Energy changes occur whenever a chemical reaction takes place. In a chemical reaction, one or more substances are changed into new substances. The starting substances are called reactants, and the new substances are the products. A solid that separates from a solution is called a precipitate. The ability of a substance to undergo chemical reactions and to form new substances constitutes its chemical properties.

10. Conservation of Mass The law of conservation of mass states that in any physical or chemical reaction, mass is neither created not destroyed; it is conserved.