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Physical and Chemical Properties of Matter
What are some physical properties?
• Color/odor
• Melting and boiling point
• Magnetic
• Conductivity
• Density
• Hardness
Graphite —the layered structure of the carbon atoms gives graphite its physical properties.
Physical Properties
Physical Changes– can be observed without changing the
identity of the substance( color, hardness, melting point & density)
– is only a change in any physical property of a substance
– matter can change from one state to another( liquid to a gas)
Some physical changes would be
• boiling of a liquid
• melting of a solid
• dissolving a solid in a liquid
• grinding or crushing
• Condensation - when gas becomes a liquid
Chemical Properties and Chemical Change
• Chemical properties of a substance are defined by the chemical changes it undergoes.
• These properties, then, must be determined using a process that changes the identity of the original substance.
• Chemical change or chemical reaction is the transformation of one or more atoms or molecules into one or more different molecules.
Sure Signs of a Chemical Change
• Chemical changes identify chemical properties.
• Production of heat/burning
• Change in color or odor
• Gas Produced (not from boiling!)
• Precipitate – a solid formed by mixing two liquids together
• New substance has been produced that is different from the original substance
• Reduction of 1 substance into 2 (breaking down of the original substance)
Some Examples of Physical vs. Chemical
Properties• Examples:
– melting point
– flammable
– density
– magnetic
– tarnishes in air
physical
chemical
physical
physical
chemical
Some Examples of Physical vs. Chemical
Reactions• Examples:
-rusting iron
-dissolving in water
-burning a log
-sublimation
-grinding spices
Chemical and
Physical Change
Practice Quiz #1
Chemical
Physical
Chemical
Physical
Physical
SolidFixed VolumeFixed Shape
Least Kinetic Energy
LiquidFixed Volume
No fixed shapeModerate
Kinetic Energy
GasNo Fixed VolumeNo Fixed Shape
Most Kinetic Energy
Melting
BoilingEvaporating
Freezing Condensing
Sublimation
Deposition
Create you own flow map on a piece of copy paper. Underneath your map, explain all of the physical changes and underline the transition words.
For example: Solids melt into liquids.
Physical Properties and Changes• The characteristics of a substance that can be observed
without changing the identity of the substance are called physical properties.▫ Examples:
Color Shape Texture Volume Mass Density
• A physical change is any change in any physical property of a substance, not in the substance itself.▫ Examples
Breaking a piece of clay Stretching a rubber band Melting ice into liquid water Dry Ice sublimating into gas
Chemical Properties and Changes
• Chemical properties describe how substances can form new substances.
• A chemical property is any of a material’s properties that becomes evident during a chemical reaction.▫ Examples:
Combustibility (ability to burn) Easily oxidized (ability to rust) Toxicity (level of harm to organisms) Reactivity with other chemicals Types of chemical bonds that will form
• The change of one substance into another substance is called a chemical change.▫ Examples:
The burning of wood The rusting of iron Mixing baking soda and vinegar to produce carbon dioxide gas
Physical and Chemical Changes
Indicators of a Chemical Change
• Color Change▫ Can be tricky to interpret▫ Some color changes are just a mixture, not a chemical change
Physical change – mixing food coloring into water (mixture) Chemical change – iron rusting due to oxygen (something new)
• Gas produced▫ Has to be a new substance, not boiling!
• Temperature change▫ Gets hot – exothermic reaction▫ Gets cold – endothermic reaction
• Precipitate formed ▫ A solid is formed when reacting two or more fluids
• Odor change▫ A new smell!
• Light or sound production▫ Boom!
Compounds and Mixtures
Compounds Mixtures
2 or more substances
Matter/Mass
Can be separated
New properties;
atoms bond
Ratio of elements
Separated by breaking
bonds
No specific ratio;
HeterogeneousHomogeneous
Retain properties of original substances
Separated by physical
means