Transcript Chemical Change

CHEMISTRY
Unit 3 & Unit 4
Review
Element
An element is a pure
substance made of only
one kind of matter.
The Periodic Table lists all
the known elements
Element Cube
Each element on the
Periodic Table gives
information about the
element
Know how to find:
Protons (5)
Electrons (5)
Atomic Mass (11)
Neutrons (Atomic Mass-Protons = 6)
Show me…
Groups stay together
Period!
1
1 Group
1
18
2
13 14 15
2
3
3
4
4
55
5
66
4
5
6
7
Period
Rare
Earth
Rare
Earth
6
7
7
88
9 1010 11 12
1
16 17
Mixture
A substance of two or more elements mixed
together. Substances are held together by physical
forces, NOT chemical. Can be easily separated.
MIXTURE OF CANDY
TRAIL MIX
SALAD
SALT WATER
SOLUTION
Compound
A substance made by chemically combining two or
more elements. Can only be separated by chemical
means NOT physical. Chemical and physical
properties are different than the elements they are
made from.
Table Salt (NaCl)
Water (H2O)
Alkaseltzer (Sodium
Bicarbonate – NaHCO3)
Table Sugar
(C12H22O11)
Physical Properties
A property that can be
observed, measured or
changed without changing the
substance itself
Examples of
Physical Properties
•
•
•
•
•
•
Odor
Density
Mass
Volume
State
Color
Chemical Properties
A property of matter that describes a substance based
on its ability to change into a new substance with
different properties.
Poisonous
Gas
+
Explosive
Powder
=
Table
Salt
Examples of
ChemicalProperties
•
•
Flammability
Reactivity
Physical Change
A change that affects
one or more physical
properties of a
substance
Chemical Change
A change that happens when
two or more substances are
changed into one or more new
substances with different
properties.
Evidence of
Chemical Reactions
•Temperature Change
•Heat is absorbed by the substances
causing the temperature to decrease
•Heat is released by the substances
causing the temperature to increase
Evidence of
Chemical Reactions
•Fizzing
•When a gas is formed it may
try to escape causing bubbles
Evidence of
Chemical Reactions
Chemical
Change
•Color Change
•This is evidence of a
chemical reaction only when
the other properties have also
changed.
Not a
Chemical
Change
Evidence of
Chemical Reactions
•Precipitate Formed
•Precipitate is a solid
substance formed when
liquids are combined
Evidence of
Chemical Reactions
•Light
•When a new substance is
formed light energy can be
produced.
Know Chemistry Vocabulary #5
1.
Oxidation - The combination of a
substance
with oxygen and will
form rust or tarnish.
2.
Substance - that of which a thing
consists; physical matter or material
3.
Chemistry – The scientific study of
the structure, properties, and
reactions of the
chemical
elements and the compounds they
form.
4.
Chemist - A scientist specializing
Frying an egg
Chemical Change
Red paint + Yellow paint =
Orange
Physical change
Effervescent tablets
bubbling
Chemical Change
Melting butter
Physical Change
Bending a paper clip
Physical Change
Sanding wood
Physical Change
Copper tarnishing (notice green
on
2nd coin)
Chemical Change
Baking a Cake
Chemical Change
Explosion!
Chemical Change
Mixture of apples &
watermelon
Physical Change
Eating & Digesting Food
Chemical Change
Can being Crushed
Physical Change