C HEMICAL AND P HYSICAL R EACTIONS

P HYSICAL P ROPERTIES A characteristic of matter that can be observed without changing the substance into another substance Examples: Freezing Boiling Melting Hardness Color Shine flexibility Solubility

C HEMICAL P ROPERTIES Characteristics of a substance that describe its ability to change into a new substance Examples: Burning Rusting Tarnishing Changing into a new substance requires another chemical, like O 2 changing to CO 2

P HYSICAL AND C HEMICAL P ROPERTIES A CTIVITY Using the objects provided, list the physical and chemical properties of each object Create a table to classify each object based on its properties Use the equipment & substances available

A: MatchB: CrayonC: Metal Ring D Reacts with water Does not react Flammable Nonflamma ble Hard Soft Melts at room temp Evaporates Physical Properties or Chemical Properties Metallic, non-metallic, magnetic, heat conductor

P HYSICAL AND C HEMICAL P ROPERTIES A CTIVITY 2 Using the substance provided, investigate and report on its chemical and physical properties Use your Lab Book, create a table with Physical and Chemical Properties noted

P HYSICAL C HANGES The form or appearance of a substance is altered, without combining it with another substance Examples? Ice to water to steam Ice cream melts Make Kool-aid Cut paper Reversible!!!

C HEMICAL C HANGES A change in matter that results in one or more new substances Chemical in the original substance combines with another chemical to create a new substance Examples? Burning anything Baking cookies Fireworks Not reversible!!!

E VIDENCE OF C HEMICAL R EACTIONS Color change Heat given off/absorbed Change in odor Gas released Light given off

C HANGES IN E NERGY Is energy released/taken in during a physical or chemical change? Energy can be light, heat, or sound If heat energy is removed during a reaction, it is an exothermic reaction (feels hot) If energy is added during a reaction, it is an endothermic reaction (feels cold)

C OMMON C HEMICAL R EACTIONS Photosynthesis Co2 + H2O = C6 H12 O6 + O2 Respiration O2+ H2O = Co2 + H2O Combustion Rusting

M INI -L AB ! Determine whether each reaction is endothermic or exothermic Make hypotheses for each of the following: Strike a match Vinegar and antacid Write 3 observations for each Write a one sentence conclusion for each

R ATES OF C HEMICAL R EACTIONS How quickly a chemical reaction can take place Controlled by 4 things Surface Area Temperature Concentration Substances Catalysts Inhibitors

R EACTANTS AND P RODUCTS Reactants are combined together to create products What are the reactants and products in the following equations? C + 2 O CO 2 2 H + O H 2 O What do you notice about these equations? There are the same number of atoms on the left as on the right Coefficients, subscripts

B ALANCING E QUATIONS Goal- Have the same number of atoms on both sides of the equation. Rules Coefficients multiply You can not change subscripts If there is no subscript after an atom, then you know there is only 1 atom present Examples on board Practice worksheet