2. Properties
Properties of matter are like characteristics. By observing them and measuring them, we can use them to describe matter. There are two types of properties – physical and chemical.
Physical Properties: properties that can be observed directly or measured without changing the chemical identity of the substance
Ex. Mass, volume, shape, size, color, luster, hardness, etc.

3. A few you may not know about…
Physical Properties
A few you may not know about…
Melting point: temperature at which a solid becomes a liquid
Boiling point: temperature at which a liquid becomes a gas

4. A few you may not know about…
Physical Properties
A few you may not know about…
Viscosity: a fluid’s resistance to flow
A physical property only of liquids
Can change with temperature
Think “how thick it is”
Ex. Viscosity of syrup is high and of water is low

5. A few you may not know about…
Physical Properties
A few you may not know about…
Solubility: a measure of how well a solute dissolves in a solvent
Solute = what is being dissolved
(Ex. Lemonade powder)
Solvent = what is doing the dissolving
(Ex. Water)
Solution = the result
(Ex. Lemonade)

6. Physical Properties
A few you may not know about…
Density: measure of compactness or consistency of a material
Mass per unit of volume
Measured in g/cm3 or g/mL
Density doesn’t change, regardless of size
Density = mass
volume
Mass is measured in grams (g), using a scale
Volume is measured in mL or cm3, using 2 different methods

7. Finding volume to calculate density
Volume of a solid: if a regular shape, use a ruler and the appropriate geometric equation
Cube or rectangular prism: V = l x w x h
Cylinder: V = π r2 h
Measured in cm3

8. Example #1
What is the density of a 15 g box measuring 10 cm by 5 cm by 2 cm?
d = ?
m = 15 g
v = ?
d = m v
v = l x w x h
v = l x w x h
v = 10 x 5 x 2
v = 100 cm3
d = m v
d = 15
100
d = 0.15 g/cm3

9. Finding volume to calculate density
Volume of a liquid: if a liquid or an irregularly shaped solid, use a graduated cylinder (and water displacement for a solid)
Measured in mL
Water Displacement:
Put enough water in graduated cylinder to cover the object.
Record initial volume.
Add object.
Record final volume, with object in it.
Subtract Vf – Vi to find the volume of the object.
Note: Water has a density of about 1 g/mL, so anything with a density less than 1 will float when placed in water, anything with a density more than 1 will sink when placed in water. This should be something they observe/pick up from the density lab, but I just like to emphasize that here, especially for honors students.

10. Example #2 d = ? m = 8.1 g v = ? d = m v v = vf - vi v = vf - vi
A sample of aluminum is put into 10.5 mL of water. If the water rises to 13.5 mL when the aluminum is added, what is the density of the aluminum if it has a mass of 8.1 g?
d = ?
m = 8.1 g
v = ?
d = m v
v = vf - vi
v = vf - vi
v = 13.5 – 10.5
v = 3 mL
d = m v
d = 8.1 3
d = 2.7 g/mL

12. Chemical Properties
Chemical Properties: properties that can only be observed or measured by changing the chemical identity of a substance.
By observing it a new substance is formed
Ex. Toxicity, flammability, combustibility, radioactivity, etc.

13. A few you may not know about…
Chemical Properties
A few you may not know about…
Combustibility: how easily a substance will set on fire
Ex. Burning charcoal
Reactivity: how easily a substance reacts, usually with an acid or base
Ex. Fluorine gas is highly reactive and will spontaneously ignite a concrete block at room temperature
Oxidation: how easily a substance reacts with oxygen
Ex. Iron reacts with oxygen and moisture to create rust

14. Physical and Chemical Changes
Matter can undergo both physical and chemical changes.
Physical Change: a change in a substance that only affects its physical properties
Ex. Cutting, coloring, crushing, melting, boiling, etc.
Chemical Change: a change in a substance that affects its chemical properties thus a chemical reaction occurs and a new substance is formed
Ex. Burning, rusting, decomposing, etc.
Chemical Reaction: process by which the atoms of one or more substances are rearranged to form different substances

15. Law of Conservation of Matter
Matter is neither created or destroyed during a chemical change. It only changes forms.
Mass cannot be “lost”, even when a chemical reaction happens.

16. Evidence of a Chemical Change
Signs that a chemical change has occurred, resulting in a chemical reaction include:
Release of light
Temperature change
Odor change
Sudden color change
Gas given off
Sudden appearance of a solid (called a precipitate)