CLASSIFICATION OF

MATTER

CLASSIFICATION OF MATTER

Based on the make up of matter

Classified into mixtures, compounds and elements

PURE SUBSTANCES Elements – found on the periodic table

Compounds – chemical combinations of elements Cannot be separated physically but can be chemically

MIXTUREMatter consisting of two or more substances mixed together but not chemically combined

MIXTURE Properties

Substances keep their own properties

No new chemicals are formed

Properties of mixturesSubstances can be present in any amount or proportion

Substances can be separated physically

MIXTUREPhysical means

MagnetismEvaporationDissectionFilteringDistillationCentrifuge

HETEROGENEOUS MIXTURE Mixture that doesn’t appear to be the same throughout

Examples: salad, concrete, granite, pizza, sand

SUSPENSION Heterogeneous mixture in which the particles of a substance are temporarily mixed in a liquid

Examples: salad dressing, chocolate milk, muddy water

SUSPENSION Properties

Exhibits the Tyndall effectScattering of light Example: seeing a beam of light in muddy water

HOMOGENEOUS MIXTURE

Mixture that appears to be the same throughout

Examples: soda, tea, toothpaste, lotion, alloys, air

COLLOIDS

Particles that are mixed together but are not dissolved

Examples: fog, smoke, jello, mayo

COLLOIDS Properties

Any state of matter Doesn’t settle out – permanently suspended

Can’t be filtered out but can appear cloudy

COLLOIDS Properties

Particles are still large but you can’t see them

Exhibits the tyndall effect Properties are consistent throughout the sample

SOLUTION Homogeneous mixture in which one substance is dissolved in another

Examples: ocean water, soda, air, alloys (brass, bronze, steel)

PARTS OF A SOLUTION

Solute Substance that is dissolved

Usually present in smaller amounts

Solvent Substance that does the dissolving

Usually present in larger amounts

Water is the universal solvent because of it shape

SOLUTION

Properties Can’t be filtered Doesn’t settle out Particles are small and not visible

SOLUTION Properties

Properties are consistent throughout the sample

Any state of matter No tyndall effect

TYPES OF SOLUTION Saturated Solution

Solution that contains the maximum amount of solute that will dissolve

Any added solute will settle to the bottom and not dissolve

TYPES OF SOLUTION Unsaturated Solution

Solution that contains less than the maximum amount of solute that will dissolve

Added solute will be dissolved

TYPES OF SOLUTION

Supersaturated Solution Solution that contains more than the maximum amount of solute that will dissolve

Very rare

TYPES OF SOLUTION Supersaturated Solution

Can be made by slowly cooling a saturated solution to a cooler temperature

Added solute will cause the extra dissolved solute to crystallize out

SOLUBILITY Measure of how much of a solute can be dissolved in a given amount of solvent under certain conditions

SOLUBILITY

Soluble – dissolves Insoluble – doesn’t dissolve

SOLUBILITY Solubility curve – graph showing the solubility of a substance with changing temperature

SOLUBILITY Factors – increase temperature, increases solubility

– increase the pressure of a gas, increases the solubility of the gas

SOLUBILITY Factors Amount of solute already dissolved – the more substances dissolved, decreases the solubility

The nature of the solute and solvent

FOUR CLASSES OF MATTER

The four classes of matter are elements, compounds, mixtures, and solutions

HOMOGENEOUS MATTER

Appears to look similar throughout

Ex: salt, sugar, whipped cream

all parts are alike (appearance)

QUESTION

What does the prefix “homo” mean?

Name the four classes of matter.

What are the four phases of matter?

QUESTION

Milk in most stores is homogenized. What do you think this means?

HETEROGENEOUS MATTER

Matter that has different properties

Ex: soil, cereal with raisins, concrete

QUESTION

How is homogeneous matter different from heterogeneous matter?

QUESTION VIDEO Why is it better to classify matter according to make-up rather than phase? Think!

WHAT IS A MIXTURE?

A combination of substances

Two or more substances that are not chemically combined

PROPERTIES OF MIXTURES

The substances in a mixture keep their separate identities (properties)

Ex: salt/pepper, sugar/water

SEPARATING MIXTURES The substances in a mixture can be separated by simple physical means

Evaporation and filtration are used to separate mixtures

TYPES OF MIXTURES (VIDEO)

Heterogeneous mixtures are the “least mixed” of all mixtures

The different particles in mixtures are large enough to be seen

HOMOGENEOUS MIXTURES

Homogenous mixtures are “well mixed”

Particles are small and not easily recognized

QUESTION

What are two ways mixtures can be separated?

SOLUTIONS (VIDEO)

A solution is a mixture in which a substance is dissolved in another, “best mixed”

PROPERTIES OF A SOLUTION

Particles are not large enough to be seen

Evenly spread particles Particles cannot be separated by simple physical means

ALLOYS (VIDEO)

Solutions of metals are alloys

Ex: gold jewelry, brass, sterling silver, stainless steel

QUESTIONS

Describe an alloy. What are two properties of a solution?

PURE SUBSTANCES (VIDEO)

Homogeneous matter is also known as a pure substance

Properties: one kind of material with the same properties

ELEMENTS

Simplest types pure substances

Made of only one type of atom

Cannot be broken down by chemical processes or heating

WHAT IS AN ATOM? (VIDEO)

The smallest particle of an element that has the same properties of the element is the atom

CHEMICAL SYMBOLS

A short way of representing elements

Consists of one or two letters

An abbreviation for an element

QUESTION

What are two properties of elements?

What is an atom?

COMPOUNDS (VIDEO)

Pure substances made of more than one element is a compound

Ex: carbon dioxide, ammonia, sugar

MOLECULES

Two or more atoms that are chemically bonded

Smallest part of a compound that has the same properties of that compound

SEPARATING COMPOUNDS

Compounds are made of molecules

Compounds can be broken down into simpler substances by heating and electricity

QUESTIONS

How is a molecule different from an atom?

How is a compound different from an element?

CHEMICAL FORMULAS

Combinations of chemical symbols are chemical formulas (C3H7OH) (NH3)

SUBSCRIPT

A subscript is placed to the lower right of the chemical symbol

It gives the number of atoms of the element

QUESTIONS

How is chemical symbol different from a chemical formula?

CHEMICAL EQUATIONS

A description of a chemical reaction using symbols and formulas is a chemical equation

COEFFICIENT The number used to balance a chemical equation (coefficient)

“Balanced” means the same number of reactants and products

QUESTIONS

How is a subscript different from a coefficient?

CHEMICAL REACTIONS

Reactants are the substances that enter a chemical reaction

Products are the substances formed by a chemical reaction

CHEMICAL EQUATIONS

2H2+O2 (reactants) 2H2O The arrow means yields

(makes) C + O2 CO2 (products) Reactants (yield) products

QUESTIONS

What does the arrow mean in a chemical equation?

What is a chemical equation?

QUESTIONS

What is another name for a chemical reaction?

On what side of a chemical reaction would you find the reactants?

Products?