Classification of Matter

Physical Science

What is Matter?????

ANYTHING, that has mass and

volume (takes up space)

How would you sort these:

A bin of markers?

A deck of cards?

A lot filled with new cars?

HOW WOULD YOU CLASSIFY THESE TYPES OF MATTER?

How Do We Classify Matter in Science?????

Scientists like to classify things.

It wouldn’t help too much to just classify matter based on their color or smell….

One way that scientists classify matter is by its composition (what it is made of).

Ultimately, all matter can be classified as Mixtures or Pure Substances.

Classifying MATTER- we must

start by knowing that …….

The building blocks of all matter

are elements (like on the periodic

table)

Atoms are the smallest unit of

an element that maintains the

properties of that element

For example,

one atom of gold (Au) is

still gold, but if you

broke the atom into

smaller pieces,

it wouldn’t be gold

Pure Substances

An Element is a pure substances made of only one type of atom

For example,

O2 C Ca He

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Pure Substances

Compounds

A compound is a substance that

is made from the atoms of two

or more elements that are

chemically combined.

Examples: NaCl (salt)

H2O (water)

Classification of Matter

by Composition

All matter can be classified into two

categories: Pure Substances or

Mixtures

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Pure Substances

10

ELEMENT

Classification of Pure Substances

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COMPOUND

Classifying Mixtures

Mixtures

Homogeneous

(Solutions)Heterogeneous

Suspens ionColloid

Classification of Mixtures

homogeneous = mixture that has

uniform composition throughout

AKA: Solution

Every piece of a sample has identical

characteristics, though another sample

with the same components may have

different characteristics.

atoms or molecules mixed uniformly

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Page 450

Put the following definitions in your notebook

from the book:

Element

Compound and give example

Heterogeneous Mixture

Colloid and give example

Suspension and give example

Homogeneous Mixture

Then turn over the paper I gave you and

complete

Homogeneous Mixtures

(Solutions)• Solutions

– Appear Uniform

– Mixed particles are dissolved and so small that they don’t reflect light (scattering).

– Nothing settles out over time.

– Nothing filters out.

– Can be in solid, liquid, or gas form!

Examples of homogeneous mixtures

Milk, toothpaste, and mayonnaise are homogeneousmixtures.

Classifying Mixtures

Mixtures

Homogeneous

(Solutions)Heterogeneous

Suspens ionColloid

Classification of Mixtures

heterogeneous = mixture that does not

have uniform composition throughout–

you can see the different parts

contains regions within the sample with

different characteristics

atoms or molecules not mixed uniformly

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Heterogeneous mixturesYou can see the particles that make

it up.

Sand and pebbles

Oil and water

Cereal

Heterogeneous Mixtures – 2 typesHeterogeneous

• Colloids

– Looks uniform but particles aren’t really dissolved. Particles are still large enough to scatter light. Looks cloudy when light goes through it.

• Suspensions– Don’t look uniform,

filters, settles out over time, and particles scatter light.

Heterogeneous Mixtures – 2 typesHeterogeneous or solution (homogeneous)?

• How can we tell if a mixture is truly homogeneous or heterogeneous?

• SHINE A LIGHT THROUGH IT AND YOU WILL KNOW!

Tyndall EffectThis is the scattering

of light reflecting off

little particles.

Solution: cannot see

beam of light

Heterogeneous: you

can see beam of light

(reflecting off litte

particles)

Density

Density –

More dense objects will sink when

compared to less dense objects.

What do you think has the highest

density?

WATER, OIL, MOLASSES?

Density

Density – How much

matter is contained in

a certain volume

D=mass/volume

What is more dense,

a cup of unpopped

popcorn kernels or a

cup of popped

popcorn?

Bellringer 11-12-13

1. A lot of medicines are kept in dark

brown bottles (not clear) What kind of

change (do you think) is being

prevented by keeping the sunlight out?

Physical or Chemical

2. If you let saltwater evaporate, the salt is

left behind. This is a method of making

drinking water from sea-water called

desalination. Is this a physical or

chemical change?