Download Unit 2 Study Guide - Alexander`s 8th Grade Physical Science

Unit 3 Study Guide
Bozenmayer, Alexander, Albano
2014 – 2015
Anything with mass AND volume.
X
X
E
Made of only 1
type of atom
C
Two elements in
fixed amounts
C
Two elements in
fixed amounts
M
Different compounds
physically combined
Mixture that does not appear to be the same throughout
Sand, trail mix
Mixture that appears to be the same throughout
Salt water, syrup
Anything with mass AND volume.
2 or more elements that are chemically combined in
fixed amounts
X
X
Mixture that does not appear to be the same throughout
Sand, trail mix
Mixture that appears to be the same throughout
Salt water, syrup
A
C
B
D
C
P
C
Just changing shape/size.
Color change due to reaction.
C
Yeast rises due to reaction.
P
Just changing shape.
P
Phase changes are physical changes.
D
C
D
D
D
P
Just changing shape/size.
C
Color change due to reaction.
C
Yeast rises due to reaction.
P
Just changing shape/size.
P
Phase changes are physical changes.
Part 1. Elements, Compounds, Mixtures
(Study your “Graphic Organizer” notes,
and “Stations Activity”, “Elements,
Compounds, Mixtures” graded
assignment, “Elements, Compounds,
Mixtures” quiz and think back on the
sludge lab)
21. What is the definition and an
example of a heterogeneous
mixture?
• Heterogenous mixtures are made of 2 or
more elements, but keep their properties.
They are unevenly mixed and do not
appear the same throughout. Sand and
trail mix are two examples.
22. What is the definition and an
example of a homogeneous
mixture?
• Homogeneous mixtures are made of 2 or
more elements, but keep their properties.
They are evenly mixed and appear the
same throughout. Sugar water and syrup
are two examples.
23. What was the big idea for
elements, compounds, and mixtures?
Part 2. Physical/Chemical
Changes (Study your
“Physical/Chemical Change”
demo sheet, think back on
your “Physical/Chemical
Changes” graded
assignment, and “Chemistry
in a Bag” lab)
24. What is a physical property?
List some examples.
• A physical property is a characteristic of
matter such as size, shape or phase that
can be observed with your senses and
measured without changing the identity of
the substance. Some examples are color,
texture, size, phase, melting point.
25. What is a chemical
property? List some examples.
• A chemical property is a property of a
single substance that is not easily
observed, and describes how the
substance REACTS with other matter.
Examples are flammability, reactivity,
26. What is the definition of a
physical change? List some
examples.
• A physical change is when a substance
undergoes a change in some properties
but keeps MOST of its properties, and
does NOT create a new substance.
Examples: cutting paper, breaking a
mirror.
27. What is the definition of a
chemical change? List some
examples.
• In a chemical change, a NEW substance
is created, two separate substances
combine and rearrange their atoms. The
new substance will have DIFFERENT
properties. Examples are burning wood,
spoiled milk.
28. What are four hints or ways
you know that a chemical
change has occurred?
• Four hints that a chemical change has
occurred are: color change, precipitate
formed, bubbles, an energy change.
29. Are phase changes physical
or chemical changes? Why?
• Phase changes are physical because it is
still the same substance, just more or less
tightly packed, molecules moving faster or
slower.