Physical and Chemical
Changes
Matter

Matter – anything that has volume or
mass.
Atoms are the smallest unit of matter!


Volume – anything that takes up
space
Mass – the amount of matter that
something is made of
MASS

Mass

Measured in grams with a balance
Volume

Liquid Volume

measured in liters

Meniscus – the curve that
you see at the liquid’s
surface used to measure
the volume

Volume

Solid Volume

Measured in cubic meters (m3)

Cubic means “having 3 dimensions”
Remember

Inertia – tendency of all objects to
resist any change in motion

More Mass Greater Inertia


harder to move an object with a large mass
harder to stop an object with larger mass once
moving
A. Matter Flowchart
MATTER
yes
MIXTURE
yes
Is the composition
uniform?
Homogeneous
Mixture
(solution)
no
Can it be separated by
physical means?
PURE SUBSTANCE
no
Heterogeneous
Mixture
yes
Can it be decomposed
by chemical means?
Compound
no
Element
B. Pure Substances

Element


matter composed of identical atoms
EX: copper
B. Pure Substances

Compound



matter composed of 2 or more
elements in a fixed ratio
properties differ from those of
individual elements
EX: salt (NaCl)
C. Mixtures
Non-specific combination of 2 or more pure
substances.
Two Types of Mixtures
Homogeneous Mixture
Heterogeneous Mixture
even distribution of components
uneven distribution of components
EX: saline solution
EX: granite
A. Physical Property

A characteristic of matter that can be
observed or measured without changing
the identity of its matter.

can be used to separate mixtures

EX: density, color, odor, mass and volume
Chemical Property

A characteristic that indicates whether a
substance can undergo a specific
chemical change.

EX: flammability, reactivity
Physical Change


Physical changes occur when
matter changes its property but not
its chemical nature.
Physical changes could include a
change in: texture, shape, size, color,
odor, volume, mass, weight, and
density.
Physical Change
Remember!

properties remain the same

reversible

can be used to separate mixtures
Physical Change
Chemical Change


Chemical changes are changes
matter undergoes when it becomes
new or different matter.
To identify a chemical change look
for signs such as color change,
bubbling and fizzing, light production,
smoke, and presence of heat.
C. Chemical Change
Remember!

properties change

irreversible

Signs: color change, formation of a gas/solid,
release of light/heat
Chemical Change

A chemical change
occurs when fireworks
are used. Fireworks
are made of metals
such as magnesium
and copper. These
change chemically as
they light up the sky.
Density

Density describes
how much mass is
in a given volume
of a material.
Density

Solids, liquids and
gases are matter,
so they all have
density.
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.
2.
Mass is measured with a
balance or scale.
Use the displacement
method or calculate the
volume.
Density Problems
What is my Density?
Complete the following questions on a separate sheet of paper as a part of
your homework assignment.
Mass
1.
500g
Volume
50ml
2.
300g
15ml
3.
25g
5cm3