2. The study of matter and the changes that it undergoes.

3. Matter Anything that has mass and takes up space Substances Definite composition Mixtures 2 or more pure substances physically combined (each substance retains its own properties) Variable Composition

4. Substances Compound 2 or more different elements chemically combined Can be broken down chemically into its component elements 2 or more symbols Examples: NaCl Cu 3 (PO 4 ) 2 Element Can not be decomposed or broken down ONLY 1 Symbol Examples: O Ni

5. Element Atoms Nucleus Proton Neutron Electron Energy levels center outside

6. Compound Ionic: Metal and a nonmetal Covalent (Molecular): 2 or more nonmetals

7. Matter SubstanceMixture Homogeneous 1 phase of matter Uniformly mixed Solutions Will not separate Heterogeneous 2 or more different phases Not uniform Will eventually separate

8. Homogenous Aqueous: Water solution Example: Salt water Tincture: Alcohol Solution Examples: Iodine Amalgam: Mercury Solution Example: Used to be used for dental fillings Alloy: Metal Solution Examples: Steel

9. Heterogeneous Colloid: Translucent mixture Examples: Milk Muddy water Suspension: Opaque Mixture Examples: Salad dressing

10.  Diatomic elements:  exist at standard conditions as two of the SAME element bonded together  hydrogen (H 2 ), nitrogen (N 2 ) and oxygen (O 2 ), plus the halogens fluorine (F 2 ) and chlorine (Cl 2 ); the halogens bromine (Br 2 ) and iodine (I 2 ) hydrogennitrogenoxygen halogensfluorinechlorine bromineiodine  Monoatomic elements:  All the other elements  Exist as one atom

11.  Used to represent atoms, compounds, mixtures etc. in different phases.

12.  (aq) means aqueous and denotes that the compound or element attached to it has been mixed with water  Denotes a mixture  Example:  NaCl (aq)  The NaCl is dissolved in water

13. Solid  Denoted by (s) next to a compound or element  Fixed volume and shape  Molecules/atoms are close together or touching

14.  Liquid  Denoted by (l) next to a compound or element  Fixed volume, shape can change  Takes the shape of the container  Molecules/atoms are not touching and further apart

15.  Gas  Denoted by (g) next to a compound or element  Neither a fixed volume or shape  Takes the shape and volume of the container  Molecules/atoms are far apart

17.  2 or more substances physically mixed together  Mixtures can be physically separated (physically separated: there will be no change in composition of the substances)

18.  Separate a solid from a liquid

19.  Separate a dissolved substance from a liquid

20.  Separate a mixture based on attraction for the solvent

21.  Separate 2 or more liquids based on their differences in boiling points

23.  Characteristics that can be observed without changing the composition of the material Examples:  Color  Density  Melting and Boiling points

24.  Characteristics that can only be observed by changing the composition Examples:  Flammability  Combustible  Reactivity with air, water, etc

25.  A change that occurs WITHOUT a change in composition Example:  Bending  Cutting  Melting  Boiling

26.  A change in matter that occurs with a change in compostion  Also known as a chemical reaction Examples:  Burning (combustion)  Reacting with acid, base, water, etc…

27. How do you know if a chemical change has occurred?  An gas is produced (see bubbling or smell the odor)  Color changes  Precipitate is formed  Heat is released or absorbed

29. Energy Ability to do work Kinetic Energy Energy of motion Potential Energy Stored energy Temperature Measure of the Average Kinetic Energy of the particles of a sample vs. Heat Kinetic energy of the particles (always flows from hot to cold)

30. In a chemical or physical change there may be a transfer of energy (heat) Exothermic process: there is a release of energy (heat) Endothermic process: there is absorption of energy (heat)

31.  Exothermic Reactions will feel “hot”  Endothermic Reactions will feel “cold”

32. Endothermic Exothermic H 2 O(l)  H 2 O(g) endo

33.  There are three phases of matter:  Solid  Denoted by (s) next to a compound or element  Fixed volume and shape  Liquid  Denoted by (l) next to a compound or element  Fixed volume, shape can change  Takes the shape of the container  Gas  Denoted by (g) next to a compound or element  Neither a fixed volume or shape  Takes the shape and volume of the container

35.  (aq) means aqueous and denotes that the compound or element attached to it has been mixed with water  Denotes a mixture  Example:  NaCl (aq)  The NaCl is dissolved in water

36. Matter SubstanceMixture Homogeneous Heterogeneous Element Compound