Organizing matter by its physical and chemical properties.

Transcription

1 Organizing matter by its physical and chemical properties.

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3 What is Matter Anything that has mass and volume It weighs something! It takes up space! So almost everything is matter!!!

4 What things are NOT matter? Thoughts, ideas, emotions, songs, energy Just about everything else is matter

5 How Matter is Classified Memorize the diagram on the next slide Know the definitions of each term Know 3 examples of each class of matter

6 MATTER Mixtures Pure Substances Homogeneous Mixture Heterogeneous Mixture Elements Compounds **The dashed boxes are the 4 classes of matter**

7 Types of Properties Physical- characteristics that can be observed or measured without changing the identity of a substance Ex. melting point, boiling pt Chemical- relates to a substances ability to undergo changes that transform it into a different substance Easiest to see when a chemical is reacting

8 Types of Properties

9 Physical Changes in Matter change in a substance that doesn t change the identity of the substance Ex. grinding, cutting, melting, boiling Includes all changes of state (physical changes of a substance from one state to another)

10 Solid definite volume definite shape atoms are packed together in fixed positions strong attractive forces between atoms only vibrate in place

11 Liquid definite volume indefinite shape atoms are close together atoms can overcome attractive forces to flow

12 Gases indefinite volume indefinite shape atoms move very quickly atoms are far apart pretty weak attractive forces

13 Plasma high temperature state in which atoms lose their electrons Ex. the sun

14 Changes of State Energy Increasing Sublimation Melting/Fusion Vaporization Freezing/Solidification Condensation Deposition Energy Decreasing

15 Chemical Changes in Matter a change in which a substance is converted into a different substance same as chemical reaction doesn t change the amount of matter present reactants- substances that react products- substances that form

16 Energy Changes in Matter when any change occurs, energy is always involved energy can be in different forms (light, heat, etc.) energy is never destroyed or created (law of conservation of energy)

17 Energy Changes in Matter Exothermic Reaction- reaction that gives off energy (feels warm on outside) Endothermic Reactionreaction that uses up energy (feels cold on outside)

18 Pure Substances vs. Mixtures Pure substances can NOT be separated into simpler components by physical means Mixtures are easily separated into its component parts by physical means

19 Pure Substances Contain only one thing. It can t be broken down into anything else There are 2 kinds of pure substances Elements Compounds

20 Elements OMG We learned some of these already!! Simplest form of matter About 115 elements exist Can t be broken down into anything else smallest piece of an element is called an atom Examples: Carbon, nitrogen, oxygen

21 Elements Organized by properties on periodic table Each square shows the name and letter symbol for each element Usually the symbols relate to the English names but some come from older names (usually Latin) Ex: gold s symbol is Au from aurum Ex: iron s symbol is Fe from ferrum

22 Periodic Table

23 Periodic Table Two rows below the periodic table are the lanthanide and actinide series These rows fit after #57 and #89 They are only at the bottom to keep the width of the chart smaller

24 Periodic Table Groups also called families vertical columns numbered 1 18 have similar chemical properties Periods horizontal rows properties changes consistently across a period

25 Types of Elements Metals Good conductor of electricity At room temperature, most are solids Malleable- can be rolled or hammered into sheets Ductile- can be made into wire High tensile strength- can resist breakage when pulled Most have silvery or grayish white luster

26 Types of Elements Nonmetals Poor conductor of heat and electricity Many are gases at room temperature Some are solids: usually brittle, not malleable

27 Types of Elements Metalloids Has some characteristics of metals and nonmetals Appear along staircase line B, Si, Ge, As, Sb, Te All are solids at room temperature Less malleable than metals but less brittle than nonmetals Are semiconductors

28 Types of Elements Noble Gases Generally unreactive gases Far right column of periodic table

29 Compounds 2 or more elements are chemically bonded so it acts like it is just one thing so we still classify it as a pure substance Examples: Carbon dioxide (CO 2 ) Sodium chloride (NaCl)

30 Mixtures 2 or more substances put together in random proportions Substances that make up the mixture do not react or bond with each other 2 kinds of mixtures Heterogeneous mixtures Homogeneous mixtures

31 Heterogeneous Mixture Can see the different parts Examples: Italian salad dressing Lucky Charms cereal Concrete

32 Homogeneous Mixture Can t see the different parts it all looks like one thing Also called a solution Examples: Milk Tap water Air

33 What are physical means of separation???? Ways of separating things without doing a chemical reaction!

34 Methods of Physical Separation Distillation Filtration Crystallization/Precipitation Chromatography Centrifugation

35 Separation Techniques Distillation add heat and the component with the lowest boiling point turns into a gas and leaves the mixture

36 Separation Techniques Filtration- solid part is trapped by filter paper and the liquid part runs through the paper Vaporization- where the liquid portion is evaporated off to leave solid

37 Separation Techniques Crystallization/Precipitation cool mixture down or react it with something so that a solid forms that can then be filtered out or let it settle to bottom

38 Separation Techniques Decanting- when liquid is poured off after solid has settled to bottom Centrifuge- machine that spins a sample very quickly so that components with different densities will separate

39 Separation Techniques Chromatography add mixture to absorbing media; the smaller components will be absorbed quicker and will start to move away from the larger particles

40 Separation Techniques Paper Chromatographyused to separate mixtures because different parts move quicker on paper than other

41 Separation Techniques Thin Layer Chromatography

42 Separation Techniques Column chromatography

43 Separation Techniques Gas Chromatography

44 Separation Techniques High Pressure Liquid Chromatography

45 Separation Techniques Gel Electrophoresis