Matter

Properties and Composition

http://z.about.com/d/chemistry/1/0/x/c/transitionmetalsolns.jpg

So What is Matter?

• Anything that occupies space and has mass

What isn’t mass?• Energy• Ideas• Sound• And…

Properties

• Physical Property - any property that can be observed without transforming the substance into another substance

mass, color, freezing point• Chemical Property - any property that

cannot be studied without transforming the substance into a different substance

iron rusts, paper burns

Properties

• Intrinsic – does not depend on the amount of material you havecolor, solubility, viscosity, malleability, boiling point, density

• Extrinsic – depends on the amount of mattermass, volume, length

Density

• Property derived from two measurements, mass and volume

• Density = Mass/Volume• Will have a unit that contains both

mass and volume such as g/cm3, lb/gal, kg/L

• Does not depend on the size of the sample

Density

• What is the density of a sample of metal that has a mass of 34.58 g and when placed in 15.0 mL of water causes the level to rise to 22.4 mL?

34.58 gMD = = = 4.7 g/ mL

V 7.4 mL

22.4 mL - 15.0 mL = 7.4 mL

CHM 1010 PGCC Barbara A. Gage

Changes

• Physical Change - change that does not transform the substance into another substancemelting, subliming, dissolving

Changes• What were the physical changes that

you encountered in activities on Day 2?

Changes

• Chemical Change - change that transforms the substance into another substance

burning, oxidation of metal

• http://jchemed.chem.wisc.edu/JCESoft/CCA/pirelli/pages/cca1NaIHgCl2.html

Chemical Change

CHM 1010 PGCC Barbara A. Gage

From Silberberg, Principles of Chemistry, 2007

Distinguishing Between Physical and Chemical Change

PROBLEM: Decide whether each of the following process is primarily a physical or a chemical change, and explain briefly:

SOLUTION:

(a) Frost forms as the temperature drops on a humid winter night.(b) A cornstalk grows from a seed that is watered and fertilized.(c) Dynamite explodes to form a mixture of gases.

(d) Perspiration evaporates when you relax after jogging.

(e) A silver fork tarnishes slowly in air.

(a) physical change

(b) chemical change

(c) chemical change

(d) physical change

(e) chemical change