Properties of Matter

Section 4.2 of the textbook

pp. 149 -155

Physical Properties

• Physical properties are characteristics

or descriptions of a substance that may

be observed or measured.

• The substance remains the same, it is

not made into a new substance, when

you observe physical properties.

Physical Properties

• In determining the properties of a

substance, you make qualitative or

quantitative observations.

Quantitative Observations

Quantitative observations – observations

made using tools to measure various

properties of a substance numerically.

e.g. temperature, volume, mass, length,

density

Qualitative Observations

Qualitative observations – observations

that are descriptive and require no

measurement. They are usually

determined through the use of your

senses (sight, smell, taste, touch or

hearing).

**Using the senses of taste, touch and

smell may be hazardous!! WHY?

Physical Properties of Matter

Colour – is observed with your sense of sight,

and is related to the reflection of different

wavelengths of light off of the surface of an

object.

E.g. a green object is reflecting green light

which reaches your eye. For more info, go to this website:

http://www.artsparx.com/seeingcolor.html

Colour vision

When you see colour,

you are seeing the

light that reflects from

an object.

The lemon reflects

yellow light and

absorbs the other

colours of light.

Physical Properties of Matter

Texture – observed using your sense of

touch. It is how a substance feels.

Examples of textures are scratchy,

rough, bumpy, smooth.

If the substance being observed is sharp,

poisonous or corrosive, it will be dangerous to

observe this property.

Check with your teacher first

Physical Properties of Matter

Lustre – the visual property of how well a

substance shines with reflected light.

There are 2 descriptors for this property:

Shiny – the substance reflects light well

Dull – the substance does not shine with

reflected light.

Physical Properties of Matter

Clarity – the ability to see an object or light through another object.

There are three degrees of clarity:

Clarity

1. Transparent – able to see an object

and light through the object without

obstruction.

May be described as

clear.

Clarity

2. Translucent - allowing light to pass

through but diffusing it so that objects

on the opposite side are not clearly

visible, but are still

slightly visible. The

circle shown here

is translucent.

Clarity

3. Opaque – not allowing light or an

image to be seen though.

The grey side

of this oval is

opaque.

Physical Properties of Matter

State of Matter – this property

relates to the shape and volume

occupied by substances. The state

is related to how the particles in an

object are connected together.

State of Matter

Solids – maintains its shape and volume, no

matter what type of container they are placed

in. The particles pack together tightly.

State of Matter

Liquids – maintain their volume but will change

to take the shape of their container

State of Matter

Gases – take on the shape and volume of (will

fill up) their container. The particles move

quickly and randomly.

State of Matter

Physical Properties of Matter

Hardness – the ability of an

object to resist being scratched.

This property is observed by

comparing two substances.

Hardness

Objects may be hard (can scratch another substance) or soft (able to be scratched).

E.g. If a diamond is rubbed on a mirror with enough force it may scratch the mirror. The diamond is hard, and the mirror is soft.

Physical Properties of Matter

Malleability – the ability of metals to be

hammered into thin sheets, or to be

shaped (bent) without breaking.

Objects may be malleable (bendable,

e.g. aluminum) or brittle (will break on

bending, e.g. chalk)

Physical Properties of Matter

Ductility – the ability of a metal to be

stretched into a long wire.

The most ductile metals are gold, silver,

aluminum and copper.

Physical Properties of Matter

Melting Point – the temperature at which

a solid will become a liquid.

E.g. The melting point of gold is 1064 degrees Celcius

Physical Properties of Matter

Boiling Point – the temperature at which

a liquid becomes a gas.

E.g. the boiling point of gold is 2856 degrees Celcius

Physical Properties of Matter

Crystal Form – a description of the

shape of solid crystal substances.

There are a number of different shapes,

but in this course we are concerned with

only 4 crystal forms:

Crystal Form

Cubic

Crystal Form

Granular (irregular)

Crystal Form

Powder

Crystal Form

Hexagonal

Physical Properties of Matter

Solubility – the ability of a substance

(called a solute) to dissolve in another

substance (called a solvent).

Substances that dissolve are soluble.

Substances that do not dissolve are

insoluble.

Physical Properties of Matter

Viscosity – the resistance of a liquid to

flow or pour.

High viscosity liquids pour very slowly

(with high resistance to flow).

Low viscosity liquids pour very easily (with

low resistance to flow).

Viscosity

Low High

Physical Properties of Matter

Density –compares the mass to the volume of a substance (mass by comparison to size).

Density is important in determining buoyancy of one substance in another. An object must be less dense than other to float.

Density

The green liquid

is less dense

than the blue

liquid. Which

liquid is the

most dense?

Physical Properties of Matter

Conductivity – the ability of an object to carry electricity or heat. Most metals are good conductors.

A conductor carries heat or electricity well.

An insulator does not carry heat or electricity well.

Chemical Properties of Matter

Chemical properties are characteristics or

descriptions of an object determined by

reacting the substance with another

substance.

To determine chemical properties, the original

substance may be changed into a new

substance with different properties.

Chemical Properties of Matter

Combustion – the ability of an object to

burn.

In combustion reactions, a substance

burns in the presence of oxygen (the

substance reacts with oxygen in the air).

Combustion

Chemical Properties of Matter

Reaction with Acid – an object may

change its form or react (e.g. dissolve,

bubble, explode, release heat) in the

presence of acid.

Not all substances react with acid.

Light Sensitivity

Some chemicals are so unstable, that they will get enough energy from light to make them break down into other substances. Hydrogen peroxide and some prescription drugs will do this.

If the label says keep in a dark place, it is for this reason.

Light Sensitivity

Reaction with Other Chemicals

When different chemicals react, they will

produce new substances with obviously

different properties

• e.g. new gas

new colour

energy is released (heat, sound, light)

energy is absorbed (feels cold)

new solid produced (precipitate)