# Describing Matter

```Properties of Matter
Objectives
How can properties used to describe
matter be classified?
 Why do all samples of a substance have the
same intensive properties?
 What are three states of matter?
 How can physical changes be classified?

Important Vocabulary
Mass
 Volume
 Extensive property
 Intensive property
 Substance
 Physical property

Solid
 Liquid
 Gas
 Vapor
 Physical change

Describing Matter
 Begins
with observation
 Properties used to describe matter can
be classified as extensive or intensive
Extensive Properties
 Are
properties that depends on
the amount of matter in a sample
 Extensive properties include: mass &amp;
volume
Intensive Properties
 Are
properties that depends on
the type of matter in a sample
 Intensive properties include: hardness,
melting point, boiling point and color
Mass
Is the amount of matter within
an object
 Mass is usually measured in grams or
kilograms
 We use balances to measure mass

Weight
Is not the same thing as mass
 Weight is the measure of the
gravitational force upon an object
 Weight can change with location, whereas
mass cannot
 It is measured in Newtons
 Weight is proportional to an object’s mass

Volume
 Is
the space an object occupies
 The method of finding the volume of
an object varies
 How do we find the volume of a lab
table?
 How about a bottle of water?
 What if the object is a gas?
Identifying Substances
Substances are matter with uniform and
definite compositions
 Elements like gold and copper are pure
substances
 Every sample of a given substance has
identical intensive properties because
every sample has the same
composition

Physical Properties
Are properties of a substance that can
be observed or measured without
changing the composition of the
substance
 Examples of physical properties:
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State
Melting point
Boiling point
Density
Color
Hardness
Conductivity
Malleability
Physical States of Matter
All matter is made of particles
 The type and arrangement of the particles
within the matter determine its state
 Matter usually exists in 1 of 3 states of matter
◦ Solid
◦ Liquid
◦ Gas
 What is the 4th state of matter &amp; where is it
found?

Microscopic Views
Properties of the Physical States
Solids: have fixed volume and shape, rigid
structure, incompressible, and vibrate slightly
 Liquids: have fixed volume but not shape,
has the ability to flow, almost incompressible,
and takes the shape of its container
 Gases: have neither fixed volume nor shape,
particles are spaced out, compressible, and
will fill any container they occupy

◦ Vapor describes the gaseous state of a normally
solid or liquid at room temperature
Physical Changes
Are changes in which the identity of
the substances doesn’t change
 However, the arrangement, location,
and speed of the particles within the
substance may change
 Examples?
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Mini Lab Tomorrow
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