BREAKDOWN OF THE EXPERIMENTS TEACHER SIDE NOTES BREAKDOWN OF THE EXPERIMENTS

PHYSICAL PROPERTIES PHYSICAL PROPERTIES: characteristics of MATTER that can be OBSERVED or MEASURED without changing the SUBSTANCE. EXAMPLES OF PHYSICAL PROPERTIES: DENSITY MELTING POINT SOLUBILITY FREEZING POINT

PHYSICAL CHANGE PHYSICAL CHANGE: a CHANGE that alters the PHYSICAL APPEARANCEof the substance but DOES NOT change the chemical composition. EXAMPLE OF PHYSICAL CHANGE: CUTTING CRUSHING MELTING DISSOLVING

CHEMICAL PROPERTIES CHEMICAL PROPERTIES: the ABILITY or INABILITY of a substance to combine with or CHANGE into one or more NEW SUBSTANCES. EXAMPLES OF CHEMICAL PROPERTIES: REACTING FLAMMABILITY OXIDIZING PRECIPITATING

CHEMICAL CHANGE CHEMICAL CHANGE: a process involving ONE or MORE substances CHEMICALLY into new substances; called a CHEMICAL REACTIONS. FIVE INDICATORS OF CHEMICAL CHANGE: BUBBLE FORMATION(FIZZING) ODOR CHANGE COLOR CHANGE TEMPERATURE CHANGE PRECIPITATION (SOLID FORMATION IN A LIQUID REACTION)

BREAKDOWN OF THE EXPERIMENTS

CANDLE EXPERIMENT Before the experiment: the candle was a SOLID During the experiment: the candle was a LIQUID After the experiment: the candle was a SOLID This experiment demonstrated a change in STATES of MATTER. This change is classified as a PHYSICAL CHANGE.

CANDLE EXPERIMENT 3 STATES OF MATTER SOLID-TIGHTLY packed particles that vibrate against one another. Solids have a definite SHAPE and VOLUME. LIQUID-LOOSELY packed particles that freely move. Liquids have a definite VOLUME, but only takes the SHAPE of its container. GAS- FREELY moving particles that are in constant motion. Gases have no definite SHAPE nor VOLUME. A change in the state of matter represents a PHYSICAL change. Burning the candle represented a CHEMICAL change because of the CARBON DIOXDE GAS(SMOKE) produced from the fire.

ALUMINUM(Al) FOIL & SODIUM HYDROXIDE(NaOH) Aluminum is an element or compound? ELEMENT Sodium Hydroxide is an element or compound? COMPOUND Elements are located on the PERIODIC TABLE and represented by SYMBOLS. Compounds are TWO or more MORE chemically bonded elements to form a NEW substance. Compounds are represented by a CHEMICAL FORMULA.

ALUMINUM(Al) FOIL & SODIUM HYDROXIDE(NaOH) As Al and NaOH reacted the following observations took place: 1.FIZZING:bubble formation 2. TEMPERATURE CHANGE: warmer to the touch Reactions that RELEASE heat energy are called EXOTHERMIC reactions. Reactions that ABSORBS heat energy are called ENDOTHERMIC reactions. The reactions you felt can be classified as an EXOTHERMIC reaction. 3.COLOR CHANGE :turned to a grayish color The grayish color produced indicates that a NEW substance has been produced. The Al no longer exist, the new solid produced is ALUMINUM HYDROXIDE(Al(OH)3). This reaction represents a CHEMICAL CHANGE because a NEW SUBSTANCE was produced.

COPPER(II)SULFATE Dissolving the copper sulfate crystals into the water is a PHYSICAL change. Compounds that dissolve in water can produce IONS=charged atoms. This experiment represents a PHYSICAL change because no NEW SUBSTANCE was produced.

IRON(Fe) & SODIUM BICARBONATE (NaHCO3) Mixtures are PHYSICALLY made; therefore making a mixture is classified as a PHYSICAL change. In order to separate the Fe from the NaHCO3 a magnet was used. MAGNETISM is a PHYSICAL property. PHYSICAL and CHEMICAL properties cannot be CHANGED. These properties helps identify the matter. The experiment demonstrated is a PHYSICAL property of Fe.

WATER (H2O) Water boiled. Boiling represents a phase change in matter. PHASE changes are PHYSICAL changes, that change the STATES of MATTER. 6 Major Phase Changes: 1. Melting: changes from SOLID to LIQUID 2. Boiling(requires direct heat): changes from LIQUID to GAS 3. Evaporation(no direct heat required): changes from LIQUID to GAS. 4. Freezing: changes from LIQUID to SOLID 5. Condensation: changes from GAS to LIQUID 6. Sublimation: changes from SOLID to GAS INSTANTLY Phase changes can represent exothermic(release heat) or endothermic reactions (absorbs heat; cool)

SODIUM CHLORIDE (NaCl) & SILVER NITRATE (AgNO3) NaCl DISSOLVED in the water, this is a PHYSICAL change of NaCl. When ionic compounds dissolve in water IONS are formed. Ions are atoms that produce a CHARGE. POSITIVE ions means that ELECTRONS are lost. These are called CATIONS. NEGATIVE ions means that ELECTRONS are gained. These are called ANIONS. AgNO3 is added to the NaCl solution, you observed the following: COLOR CHANGE: clear to a cloudy white liquid PRECIPITATION: white solid was formed from two liquid solutions

ACID/BASE NEUTRALIZATION Vinegar(CH3COOH) is classified as an ACID. Sodium Hydroxide(NaOH) is classified as a BASE. Phenolphthalein is an INDICATOR that remains COLORLESS in an acid and turns FUSCHIA in a base. Acids are compounds that will generally be formed with a HYDROGEN atom bonding with a nonmetal or polyatomic ion. Bases are compounds that are formed when a metal bonds with a HYDROXIDE polyatomic ion. Ammonia (NH3) is one of the exceptions. When an ACID and BASE react together this reaction is called NEUTRALIZATION. Neutralization of an acid and base will always produce a SALT and WATER.