1. Physical vs. Chemical Properties
The Study of Matter

2. Reviewing MATTER Matter: anything that has mass and takes up space
Mass – the amount of matter in something
Volume – the amount of space something occupies
Which of the following is matter?
A car?
A box?
You?

3. What is a property?
Property: a characteristic of a substance that can be observed

4. Physical Property
Physical property: a property that can be observed without changing the identity of the substance.
Examples:
mass
volume
color
hardness
texture
melting point
boiling point
density
solubility
specific heat
luster

5. More Physical Properties
Malleability: the ability of metals to be hammered into a thin sheet
EX – aluminum foil sheets
Ductility: the ability to be stretched into a wire
EX- Copper wire
Magnetism: force of the attraction or repulsion that exist between like and unlike poles (North /South)

6. More Physical Properties
Electrical Conductivity: the ability to carry a charge
Conductors - allows electrons to flow easily
Insulators - materials that do not allow electricity to flow through
Semiconductors - material that has conductive properties between those of conductors and insulators

7. Special Physical Properties
Melting point: the temperature at which a substance changes from a solid to a liquid at a given pressure
Melting POINT of water = 0oC
Boiling point: the temperature at which a substance changes from a liquid to a gas at a given pressure
Boiling point of water = 100oC
Freezing Point: the temperature at which a substance changes from a liquid to a solid at a given pressure

8. Change in Phases of Matter
Occurs when there is a change in the amount of thermal energy
Vaporization - liquid goes to a gas (gains energy)
Evaporation
Boiling
Condensation - gas changes to a liquid (energy is lost)
Sublimation-solid goes straight to a gas

9. Chemical Properties
Chemical property: a property that can only be observed by changing the identity of the substance
Examples:
flammability
ability to rust
reactivity with vinegar
Combustion

10. Density amount of mass per unit of volume.
can be used to identify a substance.
density of water = 1.0g/mL

11. Density Formula
D = m/V
D = g/mL
D = g/cm3

12. Density Calculations
Ex: 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 mL
D = 2.8g/3.67 mL
D = 0.76 g/mL
This object would float in water because its density is less than water (1.0 g/mL).

13. More Density Calculations
Ex: A liquid has a mass of 25.6 g and a volume of mL. Use the table below to identify the substance.
M=25.6 g V=31.6 mL
D = 25.6 g/31.6 mL
D= 0.81 g/mL
The substance is ethanol.