BELL WORK Use the Particle Theory to briefly explain the following: 1. Solids have a hard rigid shape and a definite volume. 2. A solid substance expands when heated. 3. A puddle of water disappears on a hot summer day. 4. Gases take the shape and size of their container. 5. A balloon filled with helium gas shrinks when taken outside on a cold winter day. 6. Predict what will happen to the balloon (in #5) if it is brought back inside a warm building.

PHYSICAL PROPERTIES OF MATTER …

LEARNING GOALS  I will be able to describe physical and chemical properties of matter.  I will be able to perform density calculations.

WHAT ARE PHYSICAL PROPERTIES?  Used to describe a substance (doesn’t change what it is)  Can be quantitative (with numbers) or qualitative (no numbers)  Physical change – usually a change of state; can be reversed (no change to the particles)

QUALITATIVE PP  Luster – shiny/dull  Optical clarity – ability to allow light through  Brittleness – breakability or flexibility  Viscosity – ability or a substance to flow  Hardness – ability to scratch  Malleability – ability to be hammered  Ductility – ability to be pulled into a wire  Electrical conductivity – ability to conduct electricity

QUANTITATIVE: FREEZING, MELTING, BOILING POINTS  Involved changes of state (i.e. evaporation, condensation)  Can be looked up in tables (they are constants)

QUANTITATIVE PP - DENSITY  Measure of how much mass is contained within a given volume  Units are usually g/mL (for liquids) or g/cm3 (for solids)  Equation triangle to calculate:

EXAMPLE 1  Calculate the density of a substance that has a mass of 4.5g and a volume of 13.5mL.

EXAMPLE 2  Given the density of aluminum is 2.70 g/cm3, what volume would 200g have?

EXAMPLE 3  The density of ethanol is g/mL. What is the mass of a sample with a volume of 125 mL?

CHEMICAL PROPERTIES  Properties that describe how a substance reacts in the presence of another.  A description of a substance that is determined when the composition of the substance is changed.

 Chemical property examples include:  Ability to react with water.  Ability to react with acid.  Ability to react with air.  Ability to burn (combustibility).

LEARNING GOAL REVISIT  I will be able to describe physical properties and chemical properties of matter.  I will be able to perform density calculations.

TO DO …  P 182 #2,4,5  P 198 #1  Density Worksheet  Don’t forget that to calculate the volume of a cube, the formula is …