Do Now…
Copy the HW & list as many
elements as you can think of
(without looking at a periodic table)
HOMEWORK –
#’s ,21-23,25-28,30,32
EC=Personal Element
or Element Ad
ELEMENTS
Element – a substance that
cannot be broken down into
other substances by
chemical methods.


the simplest form of matter that
has a unique set of properties.
examples – gold, neon, copper,
astatine, carbon, bromine…
EVERYTHING ON THE PERIODIC
TABLE IS AN ELEMENT!!!
COMPOUNDS
Compound – a substance
composed of a given
combination of elements that
can be broken down into those
elements by chemical methods


ALWAYS contains DIFFERENT elements
examples – magnesium oxide (MgO),
water (H2O), sodium chloride (NaCl)…
Breaking Down Compounds
Compounds can be
broken down into simpler
substances by chemical
methods, but elements
cannot.
Ex:
When sugar is
heated,it goes through
a chemical change.
Breaking Down Compounds


Final products =
carbon and water vapor
Can then break down H2O
into H2 and O2 using
electricity
Properties of Compounds
In general, the properties of
compounds are quite different from
those of their component elements.



chlorine (Cl2)is used to kill harmful
organisms in swimming pools.
sodium vapor (Na) produces the
light in some street lamps.
sodium chloride (NaCl), commonly
called salt, is used to season or
preserve food.
Mixtures & Pure Substances
How can pure substances and
mixtures be distinguished?



A pure substance
ALWAYS has the
same composition.
Must be an element
or a compound.
Ex: water, silver



A mixture has a
variable composition.
Must be a mixture of
compounds and/or
elements.
Ex: air, granite,
chicken noodle
soup
TYPES OF MIXTURES
HOMOGENEOUS
 the same
throughout
 also called a
solution
 Ex: salt water,
brass
HETEROGENEOUS
 NOT the same
throughout
 different properties
in different parts of
the same mixture
 Ex: sand & water,
granite
REVIEW OF 3-4
(Mixtures & Pure Substances)
1.
Is milk a mixture or pure
substance?
Homogeneous mixture. It’s a
mixture of water, sugar, fats and
proteins that is usually the same
composition throughout.
2.
What do you think about
chocolate milk?
Heterogeneous mixture. It’s a
mixture of water, sugar, fats, proteins
& cocoa that usually has a lot more
chocolate on the bottom of the glass
than at the top… YUMMY 
REVIEW OF 3-3
(Elements & Compounds)
3.
Passing an electric current
through a certain substance
produces oxygen and sulfur.
This substance cannot be a(n)
a) compound.
b) mixture.
c) element.
d) solution
REVIEW OF 3-3
(Elements & Compounds)
4.
Which of the following is a
mixture?
a) sodium chloride
b) carbon dioxide
c) sucrose
d) air
REVIEW OF 3-2
(Chemical vs. Physical Change)
1.
TRUE or FALSE:
Heating water, causing it to
boil is a chemical change.
FALSE…Liquid water becomes gaseous
water when it boils, but it’s still H2O!
(this is a physical change)
Chemical changes occur when
different substances are produced.
REVIEW OF 3-2
(Chemical vs. Physical Change)
5.
A substance’s ability to
change into different
substances is called a:
a)
b)
c)
d)
physical property
physical change
chemical property
chemical change
REVIEW OF 3-2
(Chemical vs. Physical Change)
6.
Classify the following as
chemical or physical changes:
PHYSICAL
a)
gold melting
b)
natural gas burning
c)
d)
CHEMICAL
crushing an
PHYSICAL
aluminum can
leaves turning
CHEMICAL
colors in the fall
REVIEW OF 3-1
(States of Matter)
7.
Which of the following states
of matter takes the shape of
its container and has a fixed
or definite volume?
a)
b)
c)
d)
solid
liquid
gas
plasma
REVIEW OF 3-1
(states of matter)
8.
Rank the three most
commonly cited states of
matter from highest to lowest
energy:
a)
b)
c)
d)
solid, liquid, gas
liquid, gas, solid
solid, gas, liquid
gas, liquid, solid