2. Section 2.1
The Nature of Matter
Objectives
1. To learn about the composition of matter
2. To learn the difference between elements and
compounds
3. To define the three states of matter
3. Section 2.1
The Nature of Matter
A. The Particulate Nature of Matter
• Matter has mass and occupies space.
• It is composed of tiny particles called atoms.
4. Section 2.1
The Nature of Matter
B. Elements and Compounds
Elements
• Elements contain only one type of atom – elemental
copper contains only copper atoms and elemental gold
contains only gold atoms.
5. Section 2.1
The Nature of Matter
B. Elements and Compounds
Compounds
• Compounds are substances that contain two or more
different types of atoms.
6. Section 2.1
The Nature of Matter
C. The States of Matter
• Matter exists in three states:
– Solid: a rigid substance with a definite shape
– Liquid: has a definite volume but takes the shape of its
container
– Gas: takes the shape and volume of its container
7. Section 2.1
The Nature of Matter
Structure of a Solid
• Particles are held close togother in a regular
arrangement or lattice.
• Not able to move freely,but simply vibrate in
their fixed positions.
• Video Clip
9. Section 2.1
The Nature of Matter
Structure of a Liquid
• Particles are closely packed together in an
irregular arrangment.
• Able to move , flow and slide on each other.
• Video Clip
11. Section 2.1
The Nature of Matter
Structure of a Gas
• Particles are in continual straightline motion
(randomly).
• The kinetic energy of the molecule is greater than the
attractive force between them, thus they are much
farther apart and move freely of each other.
• When the molecules collide with each other, or with the
walls of a container, there is no loss of energy.
• Video Clip
13. Section 2.1
The Nature of Matter
• The Kinetic Molecular Theory explains the forces between
molecules and the energy that they possess. This theory has 3
main points :
– Matter is composed of small particles (atoms or molecules).
•
•
• Particles are moving all the time.(higher Temp. higher of
average energy
– The molecules are in constant motion. This motion is different
for the 3 states of matter.
–
14. Section 2.1
The Nature of Matter
•Solid particles are close together in a regular pattern.
•They cannot move from one place to another place.
•Solid particles are vibrating about their positions all
the time.
15. Section 2.1
The Nature of Matter
•Liquid particles are closer.
•They are moving continuously.
16. Section 2.1
The Nature of Matter
A. Physical and Chemical Properties and Changes
• Properties are used to identify and separate the substance.
• Ex: Substance = metals Properties = conduct electricity
• Matter has both physical and chemical properties.
– Chemical properties describe a substance’s ability to change
to a different substance.
– Physical properties are the characteristics of a substance that
do not involve changing to another substance.
• Examples are: shape, size and color, melting point, boiling
point
17. Section 2.1
The Nature of Matter
A. Physical and Chemical Properties and Changes
• Matter undergoes physical and chemical changes.
– A physical change involves a change in one or
more physical properties but no change in
composition.
– Ex:melting, boiling, freezing
20. Section 2.1
The Nature of Matter
B. Physical and Chemical Properties and Changes
• Matter undergoes physical and chemical changes.
– A chemical change transforms a substance into
one or more new substances.
– Ex: electrolysis
21. Section 2.1
The Nature of Matter
Objectives
1. To learn to distinguish between mixtures and pure
substances
2. To learn methods of separating mixtures
22. Section 2.1
The Nature of Matter
A. Mixtures and Pure Substances
• Matter can be classified as a mixture or a pure
substance.
23. Section 2.1
The Nature of Matter
Classification of Matter:
• Mixtures = a blend of two or more kinds of matter, each of
which retains its own identity and properties.
• - Parts can mixed together physically and usually can be
separated.
• - Contain various amounts of different substances, so the
composition needs to be specified. (% Mass = EX: 5 % NaCl
and 95 % water)
• Homogeneous (solutions): Uniform in composition
(Saltwater, air, milk, alloys)
• Heterogeneous: not uniform throughout (can be separated)
(pizza, concrete, salad)
24. Section 2.1
The Nature of Matter
A. Mixtures and Pure Substances
• A pure substance always has the same composition.
• Pure substances are of two types:
– Elements which cannot
be broken down
chemically into simpler
substances
– Compounds which can
be chemically broken
down into elements
Water is a compound. All the
components are the same—H2O molecules.
28. Section 2.1
The Nature of Matter
Summary: The Organization of Matter
29. Section 2.1
The Nature of Matter
Separation techniques of mixtures:
• Filtration = to filter a solid from a liquid
– Filtrate
– Residue
– Decant = used when the mixture consists of
substances of different densities.
• The less dense substances is carefully poured
off of the more dense one.
• Centrifugation - used when the substances have
very similar densities, or when one of the substances
consists of very fine particles suspended in a liquid.
• Electrolysis – electric current to separate water into
hydrogen gas and oxygen gas
30. Section 2.1
The Nature of Matter
B. Separation of Mixtures
Mixtures can be separated into pure substances by
various means.
• filtration
31. Section 2.1
The Nature of Matter
Chromatography
This technique separates substances (dyes and pigments) on
the basis of differences in solubility in a solvent.
Paper Chromatography = A solvent travels through paper by capillary action
and carries the pigments with it. Different pigments are deposited at different
places on the paper depending on how much they like the solvent compared to
how much they like to stick to the paper.
Solvent
Solute
32. Section 2.1
The Nature of Matter
Separation Techniques
• Distillation = to remove dissolved substances from a
liquid or to separate a mixture of liquids that have
different boiling points.
• The original liquid is heated.
• The temperature is measured.
• The vapor is collected and condensed back into a liquid.
• The new liquid is collected.
33. Section 2.1
The Nature of Matter
B. Separation of Mixtures
Mixtures can be separated into pure substances by
various means.
• distillation
