Chapter 2 Properties of Matter 2-1 Classifying Matter

Objectives 1.Classify pure substances as elements or compounds 2.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 _____(C 6 H 12 O 6 ) 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. HeterogeneousHomogeneous

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 components 1._________ 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

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/cm 3 Actual density of silver = 10.5g/cm 3 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.

Examples 1.___________ 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 reactive Nitrogen 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?