Chapter 2 Properties of Matter

Chapter 2 Properties of Matter 2-1 Classifying Matter

Objectives • Classify pure substances as elements or compounds • Describe the characteristics of an element and the symbols used to identify elements • 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 aheterogeneoussubstance? • Heterogeneous: substance whose composition is ______ uniform throughout……always a __________

What is the difference between ahomogeneous and aheterogeneous 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 • _________ • _________

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 • ________ is a process that separates materials based on the size of their particles • ___________ 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 • ___________ 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 • Change in _______ • The production of a ________ • 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?

Chapter 2 Properties of Matter