Classifying Matter Notes
Matter
Pure Substance
Element
Mixture
Compound
Homogenous
Heterogeneous
Mixtures
Matter is all mixed up! Matter is usually found in mixtures.
Mixture: a combination of different kinds of matter, in which the different kinds are NOT changed
by being put together. The parts of a mixture can be separated. They can be separated by using
the properties of the substances.
For example, if you mix jellybeans and pebbles together, the
pebbles stay pebbles and the jellybeans stay jellybeans. If you
were patient, you could pick out the jellybeans one by one and
eat them. You probably used the property of color to find the
parts of the mixture.
But a jellybean is a mixture too, a mixture of coloring, sugar,
and flavoring. Could you pick out the parts of a jellybean just
using your fingers? Probably not. Some mixtures are harder to
sort out than others, like jellybeans or salt water. Chemists are
very good at figuring out ways to separate mixtures, because
they know the properties of many different kinds of matter.
Some properties of matter:
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color
taste
melting
point
boiling point
density
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luster
hardness
mass
volume
length
shape
reactivity
Two Types of Mixtures
1. Homogenous mixtures (or solutions): the same throughout
2. Heterogeneous mixtures: different parts that are not necessarily made up of exactly the same
proportions.
Ex: A vegetable soup might give you different vegetables in every bite.
Heterogeneous VS Homogenous
There are two different substances
in this mixture.
One kind of substance in this mixture.
Homogenous
Mixture
Colloid: a mixture with larger particles that never settle. Ex: Fog, milk
Tyndall Effect: the scattering of light when shining through a colloid
Suspension: A heterogeneous mixture containing a liquid in which visible particles settle. Ex: dirty water
Substances
The parts of a mixture are called substances.
Substance: made of only one kind of matter. Each substance has its own properties which do NOT
change. This is how chemists can tell one substance apart from another and why knowing the
properties of matter is important.
There is only one kind of substance in the container to the left.
You could group them by color, density, taste, melting point,
boiling point, electrical conductivity, hardness, or by whether
they are poisonous. You could group them by state: solid, liquid,
or gas. However, whatever groups you choose, they should be
useful groups/properties that help you understand what you are
studying.
Elements and Compounds
Most substances on Earth are in the form of compounds.
Compound: a substance made of two or more elements that CANNOT be separated by physical
means. Chemists break down compounds using special chemical methods which may include heat,
electricity, and adding other substances to the compounds.
Even in the time of the alchemists, people knew that there were some kinds of substances which
were special because they could NOT be broken down. These substances, called elements were
the basic building blocks of all matter.
Elements: contain only one kind of matter. Hydrogen is an example of an element.
All other matter could be broken down into elements, but elements could NOT be broken into
anything else. These substances, such as silver, lead, mercury, tin, copper, gold, and iron, were
known to the alchemists. Gradually, more elements were discovered, and today there are 110
known elements.
To see if a substance is a compound, chemists often cause a chemical reaction. If a reaction
happens and the substance separates into two or more different substances, it was a compound.
If no reaction happens, the substance is an element.
Sorting matter into these groups turned out to be very important and helpful for learning how
matter is put together. You will learn how elements are organized.
ELEMENTS
COMPOUNDS
MIXTURES
Made up of only one kind of
atom
Made up of more than one
atom or kind of atom
Can be broken down by
chemical means
Has different properties from
elements making it up
Has same properties
throughout
Made up of more than one
kind of molecule
Can be separated by physical
means
Has same properties as
substances making it up
Has different properties
throughout
Varying amounts of elements
and compounds
Cannot be broken down
Has same properties as atoms
making it up
Has same properties
throughout
Set proportion of elements
Classification of Matter
Summary
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Matter usually occurs in mixtures, which CAN be separated.
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The parts of a mixture are substances and each substance has its own properties.
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Most substances are combined in compounds and can be broken into their component substances
using chemical means.
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Some substances are called elements and CANNOT be broken down into other substances by chemical
means.