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PROPERTIES OF MATTER
PHYSICAL AND CHEMICAL
PROPERTIES AND CHANGES
CHEMISTRY: BIG IDEAS
1. The use of elements and compounds has both positive and negative effects on society and the environment
2. Elements and compounds have specific physical and chemical properties that determine their practical uses.
What does that mean?Individual characteristics of substances determine how they are
used.
MATTER
Everything is made of matter.Your desk
Your shoes
Your lunch
To determine what type of matter something is we use our senses to make observations of its properties.
5 senses?SightSmellTouchSoundTaste
MATTER
Knowing the properties of matter means knowing how to handle it safely- especially when something goes wrong.*WHMIS
Tell me about this:
All matter has both physical and chemical properties.
PHYSICAL PROPERTIESCharacteristics of a substance that are observed with
the senses
Can be observed or measured without changing the composition of the substance
The boiling point of water is 100°C The melting point of water is 0°C Can be measured without breaking the
molecules apart into hydrogen atoms and oxygen atoms
There are 2 types of physical properties….
PHYSICAL PROPERTIES
1. Qualitative:Characteristics that can be described but not
measured (i.e. no numerical information)
Ex: the solution is an opaque, dark blue colour
2. Quantitative:Characteristics that can be measured numerically
Data represented with numbers
Ex: We have 238 ml of the solution
PHYSICAL PROPERTIESQualitative
PROPERTY EXAMPLE
Colour Blue, colourless
Odour Sweet, pungent
State Solid, liquid, gas
Texture Soft, smooth, rough
Lustre Shiny, dull
Malleable Pliable, hard, soft
PHYSICAL PROPERTIESQuantitative
PROPERTY EXAMPLE
Conductivity Ability to conduct electrons or heat
Viscosity Resistance to flow
Melting point* Melts at ______
Boiling point* Boils at ______
Density* Mass to volume ratio
Solubility Ability to dissolve other substances
Hardness Ability to scratch other substances
CHARACTERISTIC PHYSICAL PROPERTIES
Physical properties can be used to identify a substance:
Eg) The specific temperature at which a substance changes state is a characteristic physical property
Melting point: temp at which a solid turns into a liquid
Boiling point: temp at which a liquid turns into a gas
Density – Substances have a specific density ratio
Water has very unique physical properties:Can exist in 3 states at the same time
Unusually high boiling pointTemperature moderation
Very soluble!
Can dissolve a large variety of chemical substances
Liquid is more dense than solid
CHEMICAL PROPERTIES
Describe the ability of a substance to react with another substance and form a new substance
Eg. Ability of copper to turn green (oxidizing) is a chemical property
PROPERTY EXAMPLE
Reactivity -How elements and compounds react to create new chemicals or products
Combustibility
-The ability of an element or compound to burn in air
Stability -How easily a substance decomposes - More stable = longer to break down
Toxicity -Refers to the harm that exposure can cause to animals and plants
Reactivity
A substance’s tendency to react to different substances is a chemical property
Reaction with WaterSodium explosionhttp://www.youtube.com/watch?v=MTcgo46nxNECalcium carbide lighthttp://www.youtube.com/watch?v=thkgrwGgALw
Reaction with Oxygen Iron rustCombustion fire
Reaction with acids or basesBaking soda and acid produce CO2 makes dough risehttp://www.youtube.com/watch?v=Sgr9gery9dY
PROPERTY PHYSICAL?
CHEMICAL?
Red colour
Density
Flammability
Solubility
Reacts with acid to from hydrogen gas
Supports combustion
Bitter taste
Melting point
Reacts with water to form gas
Reacts with a base to form a gas
Hardness
Boiling point
Lustre
Odour
Physical Changes
Objects do not change their chemical nature
Physical properties change - texture, shape, size, colour, odour
Eg. Baseball bat
Eg. Sugar water
Chemical Changes
Atoms combine to form new molecules
One or more of the following indicates a chemical change:Change of colour
Gas produced
Energy released or consumed
Precipitate is formed
PHYSICAL OR CHEMICAL CHANGE?
PHYSICAL OR CHEMICAL CHANGE?
PHYSICAL OR CHEMICAL CHANGE? Physical change think…
Change in shape Change in appearance
Chemical change think … Burning Cooking Rusting Film processing
[Was there production of a new substance?]
PHYSICAL OR CHEMICAL CHANGE?
PHYSICAL OR CHEMICAL CHANGE?
PHYSICAL OR CHEMICAL CHANGE?
HOMEWORK
Using the tables in your notes, add an everyday example of each property