PHYSICAL & CHEMICAL
PROPERTIES & CHANGES
February 2019
PHYSICAL PROPERTY
• Properties that DO NOT CHANGE
the chemical properties
• Include
• Color
• Melting/Freezing/Boiling/Condensation
Point
• Viscosity
• Density
• Can be observed & measured
CHEMICAL PROPERTY
• Properties that DO CHANGE the
nature of a chemical
• Include
• Heat of combustion (explode)
• pH (measure of acidity)
• Reactivity with water
• Electromotive force
PHYSICAL CHANGES
• Identity of material DOES NOT change
• Ex: when you crush ice, the resulting
material is still ice
• Includes: changes in state (evaporation,
condensation, melting, boiling, freezing,
sublimation)
ADDITIONAL VOCABULARY
subduction of plates
heat loss from lava
compression of sediments
evaporation of water from
the surfaces of leaves
• condensation of water on
dust particles in the air
forming clouds and fog
• ice cracking
• spoonful of sugar is dissolved
in a cup of coffee.
•
•
•
•
• lead melting
• copper wire is cut into
smaller pieces.
• water molecule gains
enough energy to enter
the vapor phase
• antifreeze is added to a
car radiator to lower the
freezing point
• moon rocks being
converted to lunar soil
by sedimentation
QUESTION (HINT: LOOK FOR THE
WORDS INDICATING TYPE OF
CHANGE)
In the rock cycle, which of these is a physical change
involved with the formation of igneous rocks?
a. Compression of sediments
b. Subduction of plates
c. Heat loss from lava
d. All of the above
QUESTION (HINT: LOOK FOR
THE WORDS INDICATING TYPE
OF CHANGE)
Sheets of ice containing mostly pure water can be
formed by decreasing the temperature of saltwater.
Which of these best describes this change?
a.
Chemical change
b.
Nuclear change
c.
Physical change
d.
Atomic change
QUESTION (HINT: LOOK FOR
THE WORDS INDICATING TYPE
OF CHANGE)
Compounds with the same chemical
composition may have different densities
because they —
a. have differences in reactivity
b. vary in solubility
c. are able to bond with oxygen
d. exist in different phases
CHEMICAL CHANGES
• Identity of material DOES change
• Ex: oxygen combines with iron to form iron oxide
(rust)
• Object cannot return to original form
• Words to look for: Souring, rotting,
decomposing, burning, changing, forming,
producing, acid weathering, rusting,
oxidizing
ADDITIONAL VOCABULARY
• A silver bracelet tarnishes.
• A bicycle is left out in the
rain and begins to rust.
• Leaves on an oak tree
turn red as winter
approaches .
• Starches and sugars being
broken down during
energy production
• Water and carbon
dioxide being converted
to glucose
• Iron in rock combining
with oxygen to form
hematite
• Acid rain damaging
marble
QUESTION (HINT: LOOK FOR
THE WORDS INDICATING
TYPE OF CHANGE)
Which of the following is an example of a chemical
change?
a. Ice cracking
b. Sugar dissolving
c. Milk souring
d. Lead melting
QUESTION (HINT: LOOK FOR
THE WORDS INDICATING TYPE
OF CHANGE)
Which of these describes a pollution-producing process
that involves a chemical change?
a.
Coal with a high sulfur content is burned, producing
gases that cause acid rain.
b.
Chlorofluorocarbons are released, changing ozone in
the upper atmosphere into oxygen.
c. Nitrogen oxide emissions combine with water vapor,
producing nitric acid.
d. All of the above
QUESTION (HINT: LOOK FOR
THE WORDS INDICATING
TYPE OF CHANGE)
Which of these changes in rocks is NOT a
chemical change?
a. Acid rain damaging marble
b. Carbonic acid weathering limestone
c. Iron in rock combining with oxygen to form
hematite
d. An ice wedge shattering a slab of shale