Chem. 152
Dr. Saidane
Matter
 Skills you should have mastered
Conceptual
1. Define matter.
2. Distinguish atoms, ions, elements, compounds, and molecules.
3. Give the name of elements given their symbol and vice versa.
4. Distinguish physical properties and chemical properties.
5. Identify physical and chemical changes.
6. Distinguish mixtures, and pure substances.
7. Define the law of constant composition and the law of conservation of mass and energy.
8. Distinguish homogeneous and heterogeneous mixture.
Descriptive
1. Describe how matter is classified.
2. Describe the difference between gas, liquid, and solid state.
3. Describe how mixtures are separated.
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
Matter is anything that has mass and takes up space.
Matter appears in a huge variety of forms. It includes anything we can touch or see as well as
anything we cannot touch or see. Therefore the knowledge of chemistry is essential if we want to
understand how the world works.
Matter is made of atoms, elements, and compounds. It has different states, properties and
undergoes changes.
 States of Matter
Matter can be gas, liquid, or solid.
1.
Matter in the gas state has neither definite volume nor definite shape. It takes the
volume and shape of container. The particles are far apart from each other and move in
strait lines freely, randomly and rapidly inside the container.
2. Matter in the liquid state has a distinct volume independent of the container. It has no
specific shape. The particles are close to each other. They move around but not as fast as
in the gas state.
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3. Matter in a solid state has definite volume and definite shape. The particles are packed in
a definite, ordered arrangement. They can only rotate and vibrate in a fixed position.
 Classification of Matter
Matter can be classified in terms of uniformity of composition and properties of a given sample
into one of two groups: pure substances or mixtures.
1. A pure substance is made of one kind of matter. A pure substance can be an element or
compound.
a)
Every sample of a given pure substance has exactly the same characteristic
physical and chemical properties. These properties are so specific that they can
be used to identify the substance.
b)
The composition of a pure substance is the same throughout and does not vary
from sample to sample.
This characteristic is also known as the law of
constant composition or the law of definite proportions. For example, pure
water is always 11.2% hydrogen and 88.8% oxygen by mass.
A pure substance can be an element or a compound.
a) An element is a pure substance made of only one kind of atom. Elements can be
divided into three classes: Metals, Nonmetals, and Semimetals or metalloids.
Semimetals have properties midway between those of metals and nonmetals.
The elements are arranged in the periodic table. Each element has a name and a
1 or 2 letter symbol.
b) A compound is a substance that is made from the atoms of two or more elements
that are chemically bonded. They are classified as either molecular compounds or
ionic compounds. A Compound can be a molecular compound, made of non
metal atoms, or an ionic compound made of a metal and a non metal.
2. A mixture is a blend of two or more kinds of matter each of which retains its own identity
and properties. It is a form of matter that can be separated by making use of the physical
properties of the components.
a) The properties of a mixture depend on the relative amounts of the mixture’s
components.
b) Mixtures are made of various amounts of different substances of different
compositions.
Based on the uniformity of their compositions, mixtures can be classified as homogeneous or
heterogeneous.
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A homogeneous mixture, also called solution, has a uniform composition. This means that it has
the same proportion of components throughout. A salt-water solution is an example of such
mixtures.
A heterogeneous mixture has a non-uniform composition.
It has different proportions of
components throughout. An oil and water mixture is an example of heterogeneous mixture.
 Separation of Mixtures
Mixtures are separated by making use of the differences in physical properties of the components.
Techniques include filtration, distillation, and chromatography.
2.
Filtration makes use of the differences in solubility (the ability to dissolve in a liquid).
The soluble material dissolves in the liquid and passes through the filter. The insoluble
material does not dissolve and is captured by the filter. This technique can be used to
separate sugar from sand.
3.
Distillation makes use of differences in boiling points.
Distillation separates the
components of a mixture by vaporizing one or more of the components. It can be used
to remove water from salt, or remove alcohol from water.
4.
Chromatography relies on the different abilities of substances to stick to surfaces.
The mixture is separated as it travels through a surface carried by a fluid substance.
Some molecules are adsorbed more readily than other and therefore emerge later with
the carrier. This technique is the most sensitive. It allows separating, as well as
identifying the different components of a mixture.
 Properties of Matter
Properties of matter allow chemists to distinguish between substances and to separate them. A
property is a characteristic that defines an entire group or subgroup of substances such as electric
conductivity. Comparisons of several properties can be used together to establish the identity of
an unknown. There are two properties of substances:
a) A physical property is a characteristic that can be observed or measured without
changing the identity of a substance. Such properties are color, melting point, boiling
point, mass, and volume.
b) A chemical property relates to a substance’s ability to undergo changes that
transform it into different substances. For example the ability of charcoal to burn in
air is a chemical property.
 Changes in Matter
Matter can undergo physical or chemical changes.
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1. A physical change is a change in a substance that does not involve a change in the
identity of the substance. Such physical changes include cutting, melting, grinding,
and boiling a substance.
2. A chemical change is a change in which one or more substances are converted into
different substances. A chemical change is also called a chemical reaction. Such
chemical changes are the burning of charcoal, the corrosion of an iron bar, and the
baking of bread. The substances that react in a chemical change are called reactants.
The substances that are formed in a chemical change are called products.

Energy and matter
Matter has potential and kinetic energy
1. Potential energy, PE, is stored energy; it results from position or composition.
2. Kinetic energy, KE, is the energy matter has as a result of motion.
•
All substances have kinetic energy no matter what physical state they are in.
•
Solids have the lowest kinetic energy, and gases have the greatest kinetic energy.
•
As you increase the temperature of a substance, its kinetic energy increases.
•
Matter and energy cannot be created or destroyed but can converted from one form to
another.
•
Both mass and energy are conserved in chemical and physical changes.
•
This is the law of conservation of mass and energy.
The law of conservation of mass and energy states that the total mass and energy of the
universe is constant.
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Differences between mixtures and compounds
Mixture
Compound
 Components can be separated by using
 Components cannot be separated by using
physical techniques
physical techniques
 Composition is variable
 Composition is fixed
 Properties are related to those of its
 Properties are unlike those of its components
components
Differences between a pure substance and a mixture
Pure Substance
Mixture
 Every substance has the same physical and
 Properties depend on relative amounts of
chemical properties
 Uniform
different substances in mixture
composition
throughout
 Different composition for each substance
the
 May have various amounts of substances in
sample
 Constant composition from sample to
each sample
sample
Differences between the three states of matter
Gas
 No definite volume
 No definite shape.
Takes
shape of container
 Particles far apart from each
other
 Particles move around in
strait lines, freely, randomly,
Liquid
Solid
 Definite volume
 Definite volume
independent of container
 Definite shape
 No definite shape. Takes  Particles packed in a
shape of container
definite ordered
 Particles are close to each
 Particles
other
 Particles move around in
and rapidly inside the
strait
container
randomly,
arrangement
lines,
and
inside the container
can’t
move
around freely, in strait
freely,
lines. They can only rotate
slowly
and vibrate in a fixed
position.
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