12.1 Properties of Solids
 Different kinds of matter have
different characteristics.
 Characteristics that can you
observe directly are called
physical properties.
 Physical properties include
color, texture, density,
brittleness, and state (solid,
liquid, or gas).
Ex. Iron is solid at
room temp.
12.1 Properties of Solids
 A physical change is any change in
the size, shape, or phase of matter
in which the identity of a
substance does not change.
 For example, when water is frozen,
it changes from a liquid to a solid.
12.1 Properties of Solids
 Properties that can only be
observed when one
substance changes into a
different substance are
called chemical properties.
 Any change that transforms
one substance into a
different substance is called
Ex. If you leave a nail
a chemical change.
outside, it rusts.
2.2 Density
Density describes how much mass is
in a given volume of a material.
12.1 Properties of Solids
The density of a solid
material depends on
two things:
1. the individual mass of
each atom or molecule,
Carbon atoms in
diamond are packed
very tightly.
2. how closely the atoms
or molecules are
packed together.
12.1 Properties of Solids
 Paraffin wax is also
mostly carbon, but its
density is only 0.87
g/cm3.
 Paraffin’s carbon
atoms are mixed with
hydrogen atoms in
long molecules that
take up more space.
The density of paraffin is low
compared to diamond
2.2 Density
Solids, liquids and
gases are matter, so
they all have density.
The density of water
is about one gram per
cubic centimeter.
2.2 Density of common materials
Density is a property of material
independent of quantity or shape.
2.2 Density
The units used
for density
depend on
whether the
substance is
solid or liquid.
 For liquids use
units of grams
per milliliter
(g/mL)
 For solids use
density in units
of g/cm3 or
kg/m3.
2.2 Density of common materials
Liquids tend to be
less dense than
solids of the same
material.
 Ex. solder (“sodder)
2.2 Density of common materials
Water is an exception to this rule.
The density of solid water (ice) is less
than the density of liquid water.
2.2 Determining Density
 To find the density of a
material, you need to
know the mass and
volume of a solid sample
of the material.
1. Mass is measured with a
balance or scale.
2. Use the displacement
method or calculate the
volume.
Solving Problems
Calculating Density
1. Looking for:
 …the density of the candle
2. Given:
 …mass = 15.0 g; volume = 17.0 mL
3. Relationship:
 D = m/V
4. Solution:
 15.0 g ÷ 17.0 mL = 0.8823529 g/mL
# Sig. fig = .882 g/mL
12.1 Mechanical properties
“Strength” describes the ability of a
solid object to maintain its shape even
when force is applied.
12.1 Mechanical properties
Tensile strength is a measure of how
much stress a material can withstand
before breaking.
12.1 Mechanical properties
Hardness measures a solid’s
resistance to scratching.
How might you compare the hardness of these two metals?
12.1 Mechanical properties
Elasticity describes a
solid’s ability to be
stretched and then return
to its original size.
Brittleness is defined as
the tendency of a solid to
crack or break before
stretching very much.
12.1 Mechanical properties
A ductile material can
be bent a relatively large
amount without
breaking.
The ductility of many
metals, like copper,
allow then to be drawn
into wire.
12.1 Mechanical properties
Malleability measures a
solid’s ability to be
pounded into thin
sheets.
Aluminum is a highly
malleable metal.