Chapter 2Lesson 2

Properties�of�Matter

Physical Properties-Characteristics�that�can�be�observed�-�WITHOUT�changing�the�identity�of�the�substance

-Examples:�Color,�shape,�mass,�state�of�matter,�texture

Physical Properties (continued)

-Many�physical�properties�remain�constant

-Therefore,�can�be�used�to�identify�substances

-Those�that�remain�constant�are�considered�Size-Independent

-Because�they�stay�the�same�regardless �of�their�size�(independent�of�their�size)�

Melting Point-The�temperature�and�pressure�at�which�a�solid�becomes�a�liquid

-A�size-independent�property

Boiling Point-The�temperature�and�pressure�at�which�a�liquid�becomes�a�gas

-Size-independent�

-Example:�Water�will�boil�at�the�same�temperature�whether�it’s�an�ounce�or�a�gallon�

-Solids�Melt�-�Liquids�Boil

Density -Mass per unit volume of a substance

-The measure of how light or heavy an object is for its size

-Based on how heavy the individual atoms are

D = M/V (Mass divided by Volume)

-Typically measured in g/cm^3 (mass in grams, volume in cm -or- mL)

Math Practice Problems - pg.54Copy�the�question �and�answer�in�your�notes.

1)A�piece�of�tin�has�a�mass�of�16.52�g�and�a�volume�2.26�cm^3.�What�is�the�density?�

2)A�man�has�a�50.0�cm^3�bottle�completely�filled�with�163�g�of�a�slimy,�green�liquid.�What�is�the�density�of�the�liquid?�

3)A�piece�of�metal�has�a�density�of�11.3�g/cm^3�and�a�volume�of�6.7�cm^3.�What�is�the�mass�of�this�piece�of�metal?�

1)A�piece�of�tin�has�a�mass�of�16.52�g�and�a�volume�2.26�cm^3.�What�is�the�density?�

Mass�=�16.52�g

Volume�=�2.26�cm^3

Density�=�16.52/2.26�=�7.31�g/cm^3

2)�A�man�has�a�50.0�cm^3�bottle�completely�filled�with�163�g�of�a�slimy,�green�liquid.�What�is�the�density�of�the�liquid?

Mass�=�163�g

Volume�=�50�cm^3

Density�=�163/50�=�3.26�g/cm^3

3)�A�piece�of�metal�has�a�density�of�11.3�g/cm^3�and�a�volume�of�6.7�cm^3.�What�is�the�mass�of�this�piece�of�metal?�

Volume�=�6.7�cm^3

Density�=�11.3�g/cm^3

Mass�=�DV�=�11.3�x�6.7�=�75.71�g

Which is more Dense?

Volume-The�amount�of�space�an�object�occupies

-To�find�the�volume�of�a�regularly�shaped�object:

-Use�the�proper�formula�

-Ex:�Volume�of�a�rectangle�=�L�x�W�x�H

-To�find�the�volume�of�an�irregularly�shapedobject:

-Displacement�Method

What is displacement?

Juan!

Chemical Properties-A�chemical�property�describes�how�a�substance�changes�into�a�new�substance

-Either�by�combining�with�other�elements�-or-�by�breaking�apart�into�new�substances

�

Chemical Properties (continued) -Once it changes into that new substance it cannot change back

EX: Burning your paper -- turns it to ash -- cannot cool it down to turn it back to paper

-Flammability and ability to rust are also examples of chemical properties

Reactivity -The�capacity�of�a�substance�to�combine�chemically�with�another�substance

-A�chemical�property

Physical and Chemical Properties are Different-Physical�Properties

-Can�be�observed�WITHOUT�changing�the�identity�of�the�substance�

-Chemical�Properties

-Can�only�be�observed�in�situations�in�which�the�identity�(chemicals)�of�the�substance�changes

-Ability�to�change�into�something�new

Density - DemoWhat�is�the�mass�of�the�purple�piece�of�play-doh?

What�is�the�mass�of�the�green�piece�of�play-doh?�

What�is�the�volume�of�the�purple�piece?�

What�is�the�volume�of�the�green�piece?�

Do�you�think�they�will�have�the�same�densities?�Why�or�why�not ?�

What�is�the�density�of�the�purple�piece?�

What�is�the�density�of�the�green�piece?�