Presentation on theme: "Physical vs. Chemical Properties"— Presentation transcript:
1 Physical vs. Chemical Properties Part 1The study of matter
2 NC Essential Standards 8.P.1 Understand the properties of matter and changes that occur when matter interacts in an open and closed container8.P.1.1: Classify matter as elements, compounds, or mixtures based on how the atoms are packed together in arrangements8.P.1.2: Explain how the physical properties of elements and their reactivity have been used to produce the current model of the Periodic Table of Elements8.P.1.3 Compare physical changes such as size, shape and state to chemical changes that are the result of a chemical reaction to include changes in temperature, color, and formation of a gas or precipitate.8.P.1.4: Explain how the idea of atoms and a balanced chemical equation support the law of conservation of mass.
3 Reviewing MATTER Matter: anything that has mass and takes up space Mass – the amount of matter in somethingVolume – the amount of space something occupiesWhich of the following is matter?A car?A box?You?
4 What is a property?Property: a characteristic of a substance that can be observed
5 Physical PropertyPhysical property: a property that can be observed without changing the identity of the substance.Examples:lustermalleability: the ability to be hammered into a thin sheetductility: the ability to be stretched into a wiremelting pointboiling pointdensitysolubilityspecific heat
6 Special Physical Properties Melting point: the temperature at which a substance changes from a solid to a liquid at a given pressurewater = 0oCBoiling point: the temperature at which a substance changes from a liquid to a gas at a given pressurewater = 100oC
7 Chemical PropertiesChemical property: a property that can only be observed by changing the identity of the substanceExamples:flammabilityability to rustreactivity with vinegar
8 Density Density is the amount of mass per unit of volume. Density can be used to identify a substance.The density of water is 1.0g/mL
9 Density Calculations Calculations: D = m/V = g/mL = g/cm3Ex: A cube has a mass of 2.8 g and occupies a volume of 3.67 ml. Would this object float or sink in water?Mass = 2.8 g Volume = 3.67 mLD = 2.8g/3.67 mL= 0.76 g/mLThis object would float in water because its density is less than water (1.0 g/mL).
10 More Density Calculations Ex: A liquid has a mass of 25.6 g and a volume of 31.6 mL. Use the table below to identify the substance.M=25.6 g V=31.6 mLD = 25.6 g/31.6 mLD= 0.81 g/mLThe substance is ethanol.
12 Concept of Change Change: the act of altering a substance Change of state/phase – Solid, Liquid, Gas
13 Physical ChangePhysical change: a change that occurs that does not change the identity of the substanceMelting iceFreezing Kool-aidTearing paperBoiling water
14 Chemical ChangesChemical change: a change that occurs that causes the identity of the substance to changeBurningDigesting foodReacting with other substancesA chemical change is called a chemical reaction
15 Chemical Changes Cont’d Indicators of a chemical change:Evolution of lightEvolution of heatEvolution of a gasColor changeFormation of a precipitateA precipitate is a solid substance that forms as a result of a chemical reaction
16 Is it Physical or Chemical? ChangePhysicalChemicalMelting cheeseBurning woodMilk souringWadding up paperBicycle rusting