Physical vs Chemical
Changes
Ms. Conner/Ms. Fagg
• MATTER: Anything that has mass and a
volume.
• ATOMS: The building blocks of matter.
• MOLECULES: Two or more atoms that are
joined together by chemical bonds.
Physical and Chemical Changes
• A change is a substance that does not change the chemical
makeup of the substance.
• EXAMPLES:
• 1. Breaking Watermelon – Changing from one big piece into
multiple smaller pieces.
• 2. Ice Cream Melting – Changing from one state of matter to
another
Physical Change
MELTING:
• Solid
Liquid
• Shape
• Temperature
FREEZING:
• Liquid
Solid
• Shape
• Temperature
VAPORIZATION:
CRUSHING:
BREAKING:
• Shape
• Any Others?!?!?!
CONDENSATION:
• Gas
Liquid
• What else?!?!
YOUR TURN!?!?!
YOUR TURN?!?!
Characteristics of Physical Changes
• SUBSTANCES STAY THE
SAME, BUT SHAPE, SIZE
OR FORM DIFFER.
•
•
•
•
3 states of matter: Solid, Liquid, Gas
Phase changes _________ change the particles.
They ________ up with ____________.
SOLIDS: Structural rigidity and resistance to changes
of shape or volume.
• Particles of solids are tightly packed, vibrating about a fixed
position.
Phases of Matter
Matter Changes
• LIQUIDS: The only state with a definite
volume but no fixed shape.
• Particles of liquids are tightly packed, but are
far enough apart to slide over one another
**Add heat to a solid and you get…
• GAS: Made up of individual atoms, elemental molecules
made from one type of atom or compound molecules
made from a variety of atoms.
• Indefinite Shape and an Indefinite Volume
• Particles of gases are very far apart and move freely
**Add heat to a liquid and you get…
From a:
To a:
Phase Change:
Added or
Subtracted Energy:
SOLID
LIQUID
MELTING
ADDING
HEAT/ENERGY
LIQUID
SOLID
FREEZING
SUBTRACTING
HEAT/ENERGY
GAS
LIQUID
CONDENSATION
SUBTRACTING
HEAT/ENERGY
LIQUID
GAS
VAPORIZATION/
BOILING/
EVAPORATION
ADDING
HEAT/ENERGY
SOLID
GAS
SUBLIMATION
ADDING
HEAT/ENERGY
GAS
SOLID
SUBLIMATION
SUBTRACTING
HEAT/ENERGY
PHASE CHANGE = Physical Changes
• Freezing Point of Water: 32°F , 0°C
• Melting Point of Water: 32°F , 0°C
• Boiling Point of Water: 212°F , 100°C
Why are the freezing point and the
melting point the same?
***CHEMICAL CHANGES PRODUCES A NEW SUBSTANCE***
• Change that results in the formation of a new
product
• Examples:
• Rusty Car – Metal and oxygen react to form Iron
Oxide.
• Sodium metal and Chlorine gas react to form Sodium
Chloride, Table Salt.
• Digesting food – food is broken down by stomach
acid.
Chemical Changes:
BURNING:
RUSTING:
BUBBLES/GAS FORMS:
NEW COLOR:
2 LIQUIDS FORM A
SOLID:
Take 5 minutes and try to identify some
characteristics of each of these chemical
changes.
• Process by which elements and compounds
combine to form new substances.
• Examples:
• 1. Rust
• 2. Battery
• 3. Burning Wood
Chemical Reactions: