Properties of Matter
Learning Outcome
• Investigate and describe properties of materials
Recall the different way that we classify matter
Particle Model of Matter
The particle model of matter is an important part of this unit. Recall that:
-All matter is made up of tiny particles.
-All the particles in a substance are the same; different substances are made of
different particles.
-There are attractive forces among particles-these attractions may be strong or weak.
-The particles are always moving; the more energy the particles gain, the faster they
move.
-There are spaces among the particles.
Properties of Matter
• Properties: are characteristics that can be used to describe a
substance. These properties can be Physical or Chemical
• Physical Properties
• Color, luster, melting point, boiling point, hardness, malleability, ductility,
crystal shape, solubility, density, and conductivity
• Chemical Properties:
• Describe how a substance interacts with other substances.
• i.e. reactions with acids, ability to burn, reaction with water, behavior in air, and
reduction to heat
• A chemical change always results in the formation of a different substance
• Unlike a physical change
Melting Point
• The melting point of a substance is the temperature at which it
changes from a solid to a liquid
• i.e. Ice (solid water) will melt into a liquid at Zero degree’s Celsius
Boiling Point
• The boiling point of a substance is the temperature at which its liquid
phase changes in to a gas phase
• i.e. Boiling point of Water is 100 degrees Celsius
Hardness
• Is a substances ability
to resist being
scratched. Hardness is
usually measured in
Mohs hardness scale
from 1 to 10
• Softest is 1 (Talc)
• Hardest is 10
(Diamond)
Malleability
• A substance that can be pounded or rolled into sheets is said to be malleable
• Metals such as gold and tin are malleable
• Aluminum foil is an example of a product that is made from a malleable substance
Ductility
• Any solid that can be stretched into a long wire is said to be ductile.
• i.e. Copper
Crystal Shape
• The shape of a substances crystals can help identify it.
• i.e. Silicon; diamond shape
• i.e. Salt; form cubes
Solubility
• The ability of a substance to be dissolved into another
• Sugar in Water, is highly soluble
• Oil in Water, is highly insoluble
Density
• Is the amount of
mass in a given
volume of a
substance
Conductivity
• Is the ability of a substance to conduct electricity or heat
• A substance that conducts electricity or heat is called a conductor
• A substance that with little or no ability to conduct is known as an Insulator
Chemical Properties
• Describes how a substance interacts with other substances
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Reactions with acids
Ability to burn
Reaction with water
Behavior in air
Reaction to heat
• Chemical properties are observable only when a chemical change takes place
• A chemical change always results in the formation of a different substance
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Change in Color
Change in Odor
Formation of a gas (bubbles)
Formation of a solid (precipitate)
Release of Heat
A new material is formed
The change is difficult to reverse