Chapter Two

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Chapter Two
Part 1
Classifying Matter
Properties of Matter
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The Nature of Matter
Matter is anything that takes up space and has
mass.
The word matter comes from the Latin word
materia, meaning material or stuff
First we need to ask . . .
What is matter?
Examples of Matter

• You can observe matter easily with your senses .
  . . rocks, trees, bicycles, air . . . Basically
  everything and anything!

The only thing that wouldnt be matter would be
energy (sunlight, heat, electricity). - no mass
or volume so they cant be matter!
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Elements, Molecules, and Compounds
Elements and compounds make up all the different
kinds of matter in the universe.
Elements are the simplest form of matter

• Cannot be broken down into simpler substances.
• Each element is made of atoms of the same type.
• Each has a unique set of physical and chemical
  properties.
• 117 known elements in the universe.
• Approximately 92 are found naturally on Earth.

• Six elements make up 99 of all living matter!
• Sulfur
• Potassium
• Oxygen

• Examples of Elements
• gold
• silver
• oxygen
• hydrogen

• Nitrogen
• Carbon
• Hydrogen

• aluminum
• nitrogen
• tin
• calcium

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Compounds, Molecules, and Elements
Compounds are two or more elements combined
chemically together.

• Properties are different from the properties of
  the elements that make them up.
• Elements in a compound have a fixed ratio.

Example
Na (Sodium) Soft metalexplodes in H20
Cl (chlorine) Poisonous greenish gas

Salt
Most matter in the universe is in the form of
compounds!
H (hydrogen) Explosive gas

O2 (oxygen) Explosive gas

Water

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Molecules, Elements, and Compounds
When two or more atoms combine, they form a
molecule.

• Most molecules are made of two or more atoms
• A molecule is the smallest particle of a
  substance with the same properties of
  the substance.

NOTE Compounds are different than
molecules because compound is used to
describe the substance in general, while
molecule describes the smallest
particle of the substance.
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Mixtures, Solutions, and Suspensions
A mixture is a combination of two or more
substances NOT combined chemically.

• May be a mixture of both elements and compounds
• Substances keep their unique properties and can
  be separated by physical means.

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Mixtures, Solutions, and Suspensions

• There are two types of mixtures . . .

Heterogeneous the parts of the mixture are
noticeably different from one another.
Homogeneous the parts (substances) are evenly
distributed. It is difficult to tell one
substance from another.
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Solutions, and Suspensions and Colloids
A solution is a mixture that looks like a single
substance and has the same properties throughout.
Solute The substance that dissolves in a
solution.
Solvent The substance into which the
solute dissolves.
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Solutions, and Suspensions and Colloids
A colloid is a mixture that contains both small
particles in solution and larger particles in
suspension.

• Colloids do not separate into layers.
• Colloids, like suspensions scatter light.

Milk is an example of a colloid.
In a suspension components are dispersed, but
large enough to see and settle out.
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Chapter Two
Part 2
Physical Properties
Properties of Matter
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Physical Properties

• Physical property is a property that can be
  observed without changing the identity of the
  substance.

Examples

• viscosity
• conductivity
• malleability
• hardness
• magnetism

• melting point
• boiling point
• density
• color

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Examples of Physical Properties
Viscosity of a substance is its resistance to
flow. Examples water low
viscosity honey high viscosity
Conductivity is a materials ability to allow
heat to flow. Examples metal high
conductivity wood poor conductivity
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Examples of Physical Properties
Malleability of a substance is its ability to be
hammered into a thin sheet
Melting and Boiling points are the temperatures
at which a solid becomes a liquid and a liquid
becomes a gas.
Density of a substance is the ratio of its mass
compared to its volume.
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Physical Properties to separate mixtures
Two common separation methods
Filtration process that separates materials
based on the size of their particles.
Distillation process that separates the
substances in a solution based on their boiling
points.
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Physical Change
A change in the appearance, without changing the
composition of the material.

• Can be reversible, or irreversible
• Substance may seem different, but the way the
  atoms link up is the same.

It is a physical change if . . .

• It changes shape or size

• It dissolves.

• Or the substance changes phase.

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Chapter Two
Part 3
Chemical Properties
Properties of Matter
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Chemical Properties

• Chemical property is any ability to produce a
  change in the composition of matter.

Examples of chemical properties . . .
flammability
reactivity
Materials ability to burn in the presence of
oxygen.
How readily a substance combines chemically with
other substances.
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Chemical Changes
Chemical changes occur when a substance reacts
and forms one or more new substances.
You know a chemical change has occurred when . .
.

• A change in color.

• Production of a gas.

• Formation of a precipitate.

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What kind of change is it?
physical
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What kind of change is it?

• chemical

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What kind of change is it?

• physical

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What kind of change is it?

• physical

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What kind of change is it?

• chemical

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What kind of change is it?

• physical