Download Matter

RHS
SCIENCE
TAKS REVIEW
PROPERTIES
OF
MATTER
Part 2
ATOMS
• Atomic structure
 Protons
+ charge
in nucleus
 Neutrons
no charge
in nucleus
 Electrons
negative charge
surround nucleus
ATOMS
• Atoms of the same element have
the same number of protons
• Atomic Number
# of protons
• Mass Number
protons + neutrons
Think about it . . .
What atom has 23
protons?
sodium
An atom has 15 protons and a
mass number of 33. How many
neutrons are in the atom?
18
Elements Compounds Mixtures
• Elements
» Are the the
purest
substances
on earth
» Substances
made of only one type of
atom
 Each with the same
Elements Compounds Mixtures
• Compounds
» Contain 2 or
more elements
in fixed
proportions
» Has different properties than
it’s elements
» Examples: water, table salt,
carbon dioxide, sugar
Elements Compounds Mixtures
• Mixture
» Contain 2 or more substances
in variable quantities
» Each
component
retains it’s
properties
» Ex: milk, dirt,
ice tea
Check For Understanding
Classify each of the
following as a element, compound
or mixture
C
M
E
1. distilled water
2. river water
3. oxygen and hydrogen
Chemical Vs. Physical Change
• Chemical Change
» occurs when the
chemical
properties of
a substance change
» the identity of the substance
changes
» need energy, such as heat,
light, or electricity, to happen.
Chemical Vs. Physical Change
• Physical Change
» When a substance is changed
physically
» No new
substances
are formed
» Ex: cut, melt,
freeze, mix,
dissolve, boil,
evaporate
Chemical Vs. Physical Change
• Physical Change
» Includes changes in state
Check For Understanding
Classify each of the
following as a chemical
a physical change
P
C
C
1. formation of rain
2. cooking a steak
3. rusting
or