Compounds And Elements
Classification:


Everything in the world that has a mass
is called “matter”
Matter can be classified as:
Matter
Pure Substance
Element
Ex. gold
Compound
Ex. water
Mixture
Heterogeneous
Mixture
Homogeneous
Mixture
RECALL:
Matter:

anything that takes up space & has a
mass
Ex.
 Ex.
 Ex.
 Ex.

a desk
pizza
silver necklace
oxygen

Pure Substance:
composed of a single substance with the
same properties throughout
 Ex.
water
 Ex.
table salt


Mixture:
combinations of two or more substances
that are not chemically combined (mixed)
 Easily separated
 Ex.
fruit salad
 Ex.
sugar in coffee

A pure substance can be further broken
down into an element or a compound……
Elements:







simplest form of matter
Made up of one type of particle
cannot be separated or broken down
into simpler substance
Ex.
Ex.
Ex.
Ex.
Oxygen
Aluminum
Gold
Copper

NOTE:
With chemical reactions you can go
from an element to compound &
vise versa!!!
Element
Compound
Ex. oxygen &
hydrogen
Ex. water
(H2O)
O
H
H
H
O
H
Recall, a pure substance can be further
broken down into an element or a compound
Compounds:






substance made of two or more
elements
can be separated into simpler
substance
Ex.
Ex.
Ex.
Ex.
Water (H2O)
Carbon dioxide (CO2)
Sugar (C6H12O6)
Salt (NaCl)

Recall, a mixture can
be further broken
Homogeneous
Mixture:
down
into that
a homogeneous
or a
 Mixture
looks uniform mixture
throughout
heterogeneous
mixture……
or like one substance
 Only one visible part
Ex.
 Ex.


milk in coffee
sugar dissolved in water
Heterogeneous Mixture:
mixtures that are not uniform
 can see individual parts (2 or more)

Ex.
 Ex.

salad
chocolate chip muffin
State whether the following
are examples of an
element or a compound.
A gold ring
element
Rust (Fe2O3)
compound
Carbon monoxide (CO)
compound
Aluminum Foil
element
Calcium
element
State whether the following are
examples of an element or a
compound or a mixture
A blueberry muffin
mixture
Chunky Soup
mixture
Salt (NaCl)
compound
Helium
element
Water (H2O)
compound
State whether the following pictures
represent an element or a
compound or a mixture
Element
Compound
Mixture
Compound
Which statement best
describes a compound.
A)
A pure substance that has a high
melting point.
B)
A mixture that is formed by two or
more elements.
C)
A pure substance that is formed by
two or more elements.
RECALL:
Matter
Pure Substance
Element
Ex. gold
Mixture
Compound
Ex. water
Heterogeneous
Mixture
Homogeneous
Mixture
3 types of heterogeneous mixtures
Mechanical Mixture
Collid Mixture
Suspension Mixture
Heterogeneous Mixtures
A. Mechanical – Easily see two or more parts
B. Suspension – very cloudy but solid part will
settle on bottom
C. Collid – very cloudy and solid part will not
settle out to the bottom – STAYS CLOUDY
Reactions:
Chemical Reactions can combine
elements to make compounds
(synthesis reaction)
OR
Chemical Reactions can break apart
compounds into its elements
(decomposition reaction)




If you see mass,
the ONLY thing
Synthesis Reaction: you know is that a
compound was
made!!!
Makes a new substance
Sign of a chemical change
Increase in mass
Ex.
+


Ex.
+

Decomposition Reaction:





Two or more substances produced
If you see
Sign of a chemical change
mass, the
Decrease in mass
ONLY thing
Ex.
you know is
that you

+
started with
a
Ex.
compound!

+
You a leave a 2g copper penny outside.
Over time, the penny becomes green in
color & its mass is now 2.5g.
Which statements below are true?
A) A chemical change occurred
TRUE
B) A physical change occurred
C) A compound was made
D) An element was made
TRUE
You have 5g orange powder which you
heat. As the powder is heated you
noticed that a gas is given off & a silver
liquid is produced. After heating you only
have 1g of the orange powder left.
Which substance was definitely a
compound? Why?
orange powder
decrease in mass
production of two
substances
A grey colored solid is
heated. The following
observations were recorded
State
Color
Texture
Mass
Before Heating
After Heating
solid
grey
smooth
1.75g
solid
black
granular
2.5g
What statement is DEFINITELY true?
A) The solid after heating is an element
TRUEB) The solid after heating is a compound
C ) The solid before heating is an element
In a lab you heat 50g of a white powder
in an open container. Over time, you
obtain a yellow substance with a mass
of 65g.
Which statement is definitely FALSE?
A)
The white powder could be an element
B)
The white powder could be a compound
C)
The yellow substance could be an element
D)
The yellow substance could be a compound

Mixture:


Pure Substance


A single substance with the same properties
throughout
Element


2 or more components brought together that
can be separated physically
Simplest form of matter that can not be
broken down
Compound

2 or more elements chemically combined

To identify elements or compounds:


If mass increases, you know that
you have made a compound
If mass decreases, you know that
you started with a compound
Activities



Physical Science Worksheet #3
Student Study Guide- Module 1.19
to 1-22
Other Activities:

Science Quest Textbook – page 31 – 33
References




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Student Study Guide – Physical Science
416/436 - MEQ
Science Quest – Grenier, Daigle,
Rheaume – 1998, Cheneliere
http://www.elmhurst.edu/~chm/vchembo
ok/101Aatoms.html
http://www.elmhurst.edu/~chm/vchembo
ok/103Acompounds.html
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