The Physical Properties of Matter

Objectives: Identify six examples of physical properties of matter. Describe how density is used to identify different substances. List six examples of physical change. Explain what happens to matter during a physical change

What is a physical property of matter? A property that can be observed or measured without changing the identity of that matter Ex: Color, odor, shape, size, volume, etc.

We use physical properties every day. If your shirt matches your skirt (color) If your book fits in your bag (volume)

More examples of physical properties Thermal conductivity Density Ductility State Solubility malleability

Thermal Conductivity Definition: The ability to transfer thermal energy (heat) to something else Example: Coffee in a special cup (poor conductor) to prevent heat transfer to our hands

State The form in which matter exists: solid, liquid, gas Definition: Example: Ice = Solid Water = Liquid Helium = Gas

The ability to be pounded into thin sheets Malleability Definition: The ability to be pounded into thin sheets Example: Aluminum can be pounded flat to make aluminum foil

Ductility The ability to be drawn into thin wires Definition: The ability to be drawn into thin wires Example: Copper is used to make wires

Solubility Definition: The ability for one substance to dissolve into another substance Example: sugar dissolves in coffee

Density Mass per unit volume Definition: Mass per unit volume Example: Lead is used for fishing weights because it is more dense than water

More information about density... Density = The amount of matter in a given space or volume Density = m Mass v Volume

More information about density... Most substances have a unique density: Water = 1.00 g/mL Gold = 19.32 g/mL (See page 47 Table 1) So density helps us in identifying substances Moreover, knowing the density of a substance can tell you if the substance will float or sink in water.

If the density of an object is less than the density of water, the object will float. If the density of an object is more than the density of water, the object will sink.

The Magic Triangle m D V Answers are expressed in g/m3 or g/cm3 or g/mL or g/L or kg/m3 etc.

A physical change is change that affects one or more physical properties of a substance. Page 48 figure 6

More examples of physical change Breaking of a bottle Melting of an ice cube Freezing of water Cutting a piece of an apple Crushing a can Dissolving sugar in water

Matter and physical change Physical change does not change the identity of the matter involved. Example, melting a stick of butter. -Although the shape and state of butter has changed, the butter is still butter!

Open your books page 49 Questions 1,2, 3, 4, 5, 6, 7, 8