Chapter 2 Properties of Matter 2-1 Classifying Matter

Chapter 2 Properties Chapter 2 Properties of Matterof Matter

2-1 Classifying Matter2-1 Classifying Matter

Objectives1. Classify pure substances as

elements or compounds2. Describe the characteristics of an

element and the symbols used to identify elements

3. Describe the characteristics of a compound

Pure Substances• Matter that always has exactly the same

composition is classified as a __________substance.

• Every sample of a given substance has the same properties because a substance has a fixed, _______ composition.

• Ex – Table ______ (Na) and _____(C6H12O6)• Can be classified into _______ and ______

Elements• ________ is a substance that cannot be

broken down into simpler substances.• _________are the smallest particle of an

element.• An element has a fixed composition

because it contains only_______type of atom.

Examples of Elements• Most are ______– Aluminum (Al)

• Some are _______– Carbon (C)

• Two are liquids are room temperature – ________ (Br) and________ (Hg)

Symbols for Elements• The ______ letter is always

capitalized• If there is a _______ letter it is not

capitalized -Na (sodium)• If the symbol contains only one

letter, it is _______ capitalized - C

Compounds• A _________ is a substance that is made

from two or more simpler substances and can be broken down into those simpler substances.

• A compound always contains ______or more elements joined in a fixed proportion.

• Ex. Water – ______

Mixtures• The _________ of a mixture can

vary because of composition of a mixture is not fixed.

• Example - ________

Beaker Breaker!!1.) Can an element or a compound be

broken down into simpler parts?

2.) What is an example of a pure substance?

3.)What are the building blocks of elements?

What is a mixture?• Variable combination of____ or

more pure substances.

Heterogeneous Homogeneous

What is the difference between a homogeneous

and a heterogeneous substance?

•Heterogeneous: substance whose composition is ______ uniform throughout……always a __________

What is the difference between a homogeneous and a heterogeneous substance?

•Homogeneous: substance that is __________ (same) in its composition

A mixture may be…•Homogeneous•(______)

•Heterogeneous•(________)

Solutions• When substances ________ and form a

homogeneous mixture, the mixture that forms is called a_________.

• Ex: ____ water and _________ wiper fluid

• _______ passes through liquid solutions without being scattered in all directions

Suspensions• A heterogeneous mixture that

________ into layers over time is called a _________.

• Ex: Shaking a jar of _______ and ______

Colloids• A________contains some particles that

are intermediate in size between the small particles in solution and the larger particles in a suspension.

• _______ is a colloid of water droplets in air

• _________ of light is a property of a colloid

Beaker Breaker!!1.) When substances dissolve and form a homogeneous

mixture, the mixture that forms is called a___________.

2.) Is fog an example of a colloid or a suspension?

3.) A heterogeneous mixture that separates into layers over time is called a_____________

Solutions Cont.• Recall that a solution is a

homogeneous mixture of two or more substances

• Two components1. _________2. _________

Solutes• A ________ is a substance whose

particles are dissolved in a solution.

Solvents• The substance in which the solute

dissolves is called the ________.

Example• _______ solution• Solute = ______• Solvent = _______

Beaker Breaker!!1.) A__________________is a substance whose

particles are dissolved in a solution.2.) The substance in which the solute

dissolves is called the ___________________.

3.) sugar in water – circle the solvent and underline the solute

2-2 Physical Properties• A _________ property is any

characteristic of a material that can be observed or measured without changing the composition of the substances in the material

Examples of physical properties

1. 2. 3. 4. 5. 6. 7.

Viscosity• The tendency of a liquid to keep

from flowing – __________ to flowing is called ________.

• Example - ________

Conductivity• A material’s ability to allow _______

to flow is called _____________• Example : Metals = ______

conductivity or also know as _________

• Stirring soup with a________spoon verses wooden spoon

Malleability• Malleability is the ability of a solid

to be_________ without shattering.

• Ex gold and ___________

Hardness• One way to compare the hardness

of two materials is to see which of the materials can _________ the other.

• Ex: Kitchen knife (stainless steel) scratching _________

Melting Point and Boiling Point

• The temperature at which a substance changes from a _______to a ______ is its ________point.

• The temperature at which a substance __________ is its _______point

• Ex: _______ at 0 degrees Celsius and 100 degrees Celsius

Density• _______can be used to test the purity of

a substance.

• Density = Ex: Silver coin density = 9.9g/cm3

Actual density of silver = 10.5g/cm3

Coin is not _______silver

Beaker Breaker!!1.) Name one of the seven physical

properties________________2.) Which physical property is defined as a

material’s ability to allow heat to flow?

3.) Aluminum and Gold are examples are what physical property?_____________

Using Properties to Separate Mixtures

1. ________ is a process that separates materials based on the size of their particles

2. ___________ is a process that separates the substances in a solution based on their _______ points.

Recognizing Physical Changes

• A __________ change occurs when some of the properties of a material change, but the substances in the material remains the same.

• Ex: slowly heating butter in a pan –changes from solid to liquid, but the substance in the butter remains the _________.

• _________ a tomato• Crumpling a piece of paper

Chemical Properties• A ________ property is any ability to

produce a change in the___________ of matter.

• Chemical properties can be observed only when the substances in a sample of matter are ________ into different substances.

Examples1. ___________ is a material’s ability

to burn in the presence of oxygen.

Ex. __________ and _________

Reactivity• The property that describes how readily

a substance combines chemically with other substances is ____________.

• Example – _________ in air________ is highly reactiveNitrogen has a ______ reactivity- _______ is another example

Recognizing Chemical Changes

• A ________ change occurs when a substance reacts and forms one or more _______ substances.

Examples: cake ______ in oven leaves on trees change ____ food ________ in your

stomach

Three common types of evidence

1. Change in _______

2. The production of a ________

3. The formation of a _________

A change in color• Ex: ________tarnishing a ________ burning then turning

black and shrivels

Production of a Gas• Ex: Combining vinegar and baking

soda – _________of carbon dioxide form

Formation of a Precipitate

• Any __________that forms and separates from a liquid mixture is called a _____________.

• Ex: when acid is added to _____, proteins in the milk undergo a chemical change that alters their structure, causing them to stick together in ___________

Is a change chemical or physical?

• When matter undergoes a chemical change, the _________ of matter changes.

• When matter undergoes a physical change, the composition of the matter remains the________.

Beaker Breaker!!1.) What is one of the three common types of evidence

of a chemical change?

2.) Any solid that forms and separates from a liquid mixture is called a__________

3.) Gasoline and paper is an example of what chemical property?