Lesson 1 Pure Substances And Mixtures - Calendar
Grade 7 ScienceModule 2, Lesson 15Lesson 1Pure Substances and Mixtures(Heterogeneous and Homogeneous)Vocabulary matter particle theory ofmatterLearning Outcomes pure substanceAfter completing this lesson you will be able to mixtureQidentify the difference between a pure substanceand a mixture, according to the particle theory ofmatterWhat is the Difference Between a Pure Substance and aMixture?Matter is anything that takes up space and has mass. Asdiscussed in Module 1, the particle theory of matter statesthat all matter is made up of tiny particles.A pure substance contains only one type of particle.Substances don't usually occur in their pure form in nature, soin order to obtain pure substances, people must refine rawmaterials. Some examples of pure substances are gold,aluminum, and sugar.table sugarsugar beetbauxitealuminum foil
6Module 2, Lesson 1Raw materials, and many substances around us, are actuallyexamples of mixtures. Mixtures are substances that consist ofcombinations of two or more pure substances, or differentparticles. Mixtures can be in the form of solids, liquids, and/orgases, in any combination.pure substancePracticeSix of the possible kinds of mixtures are:a) a mixture of gasesd) a mixture of gases in a liquidb) a mixture of liquidse) a mixture of solids in a liquidc) a mixture of solidsf) a mixture of solids and gasesIn each picture on the following page, there is an arrow thatpoints to a mixture described in the list above. Write the letterthat shows what kind of mixture it is below each picture.Grade 7 Science
Grade 7 ScienceModule 2, Lesson 1F r o m Science Workshop Series: Chemistry Mixtures and SolutionsbySeymour Rosen. 1992 by Globe Fearon, an i m p r i n t of Pearson Learning, ad iv is io n of Pearson Education Inc. Used by permission.7
Grade 7 ScienceModule 2, Lesson 18Questions: True or False?Are the following statements true or false?True1. A i r is a m i x t u r e .2. Gold is a pure substance.3. W a t e r f r o m a l a k e i s a p u r e substance.4. A pure substance contains particles that areall alike.5. Two d i f f e r e n t gases t o g e t h e r m a k e u p amixture.False
Grade 7 ScienceModule 2, Lesson 29Lesson 2Solutions, Solutes, and Solventsy. :::# Vocabulary' :;;: mechanicalmixture heterogeneousmixture solution homogenousmixture solute soluble solventLearning OutcomesAfter completing this lesson you will be able toQexplain the difference between a solution and amechanical mixtureQrecognize that solutions are homogenous mixtures andmechanical mixtures are heterogeneous mixturesQdescribe solutions by using the particle theory of matter identify the solute and solvent in a solutionQidentify common substances that are examples of puresubstances, solutions, and mechanical mixturesWhat is a Mechanical Mixture?Mechanical mixtures are mixtures composed of two or moresubstances that remain visible even after they are mixed. Thinkof how granola cereal or trail mix looks — the individualingredients such as raisins, nuts, and dried fruit remain visibleeven after mixing. Concrete is another example of a mechanicalmixture — the components of the sand, lime, and water used tocreate it often remain visible.Mechanical mixtures are also known as heterogeneousmixtures (uneven mixtures). A salad dressing made of oil andvinegar is considered a heterogeneous mixture because itscomponents — oil and vinegar — remain separate and distinct.Think about a chocolate chip cookie. Would it be considered amechanical mixture? Why or why not? Explain your answer.
10Grade 7 ScienceModule 2, Lesson 2T h e Magic of SolutionsSolutions are a type of mixture in which the pure substanceswithin the solution mix together so well that they give theappearance of only one substance.When sugar is mixed with water, for example, the sugar seemsto "disappear." Yet, if you were to taste the mixture, you wouldknow the sugar was still there. Also, if you were to place thesolution in a shallow dish and allow the water to evaporate, thesugar would reappear.Air is an example of a solution you can obtain by dissolvingcarbon dioxide, oxygen, and argon into nitrogen gas. Brass isalso a solution, made up of copper and zinc. Remember,solutions can be any combination of the three states of matter— solid, liquid, and gas.When vinegar and water are combined, it appears as if thesubstance is the same throughout. These types of mixtures arecalled homogenous mixtures. In these mixtures, the particlesin a solution spread out evenly and do not settle upon standing.We can use the particle theory of matter to illustrate theconcept of solutions and mechanical mixtures. Here is anexample of a solution, which is evenly mixed: pure substanceilC D H C D lOi C D fU C D HCD H CD i o iH CD H CD HsolutionCDpure substance
Grade 7 ScienceModule 2, Lesson 211Here is an example of a mechanical mixture, which appearsuneven after mixing:1lll lj 'J f' j li1j Ji 'j j JI11f ill:} Pill jljllpure substance1 1 1 1 1 1 A A El ElLU LU A A EH AA A n AsmAA A A A A A AA A A ArffifrhlA ill illt'Sv ;lmechanical mixturepure substanceSolutions have two parts: a solute and a solvent. A solute is thesubstance that dissolves. (With the sugar water example, thesugar is the solute. Because sugar dissolves in the water, sugaris described as "soluble.") A solvent is the substance in whichthe solute is dissolved. (In the case of the sugar water example,the water would be the solvent.)According to the particle theory of matter, it is the attractionbetween the particles of a solute and solvent that keeps them insolution.
12Module 2, Lesson 2Grade 7 ScienceQuestionsPart 1: Liquid Solutions and the States of MatterA l l the examples in Figures A, B, and C are liquid solutions.Remember, there are three states of matter — solid, liquid, andgas.1. Name the states of matter ofthe substances in this liquidsolution (Figure A).and2. The solute is thesolid, liquidFigure A3. The solvent is thesolid, liquidName the states of matter ofthe substances in this liquidsolution (Figure B).and5. The solute is thegas, liquidFigure B6. The solvent is thegas, liquidF r o m Science Workshop Series: Chemistry Mixtures and SolutionsbySeymour Rosen. 1992 by Globe Fearon, an i m p r i n t of Pearson L e a r n i n g , adivision o f Pearson Education Inc. Used by permission.
13Module 2, Lesson 2Grade 7 Science7. Name the states of matter ofthe substances in this liquidsolution (Figure C).andFigure CNote: In solutions where all theparts are liquid, we usually do notname the solute and solvent.Part 2: Completing SentencesChoose the correct word or term for each statement. Write yourchoice in the spaces provided.1. A liquid solution has at least one.solid, l i q u i d , gas2. The solute in a liquid solutionmust be a gas, m u s t be a solid, can be any state of m a t t e r3. In solutions of liquids and solids or of liquids and gases, thesolvent is always the.solid, l i q u i d , gas4. In solutions of all liquids, we usually .name the solute and solvent.do, do not
14Module 2, Lesson 2Grade 7 SciencePart 8: Which Are Liquid Solutions?Ten mixtures are listed below. Some are liquid solutions, someare not. Think about each mixture, then fill in the boxes.Mixture1.sugar water2.muddy water3.salty water4.pebbles in water5.instant coffee drink6.orange juice7.oil and water8.instant tea drink9.ocean water10.Do the substances I f the substances dissolved,dissolve? (Writename the solute name theYES or NO.)(or solutes).solvent.vegetable soupPart 4: Fill in the BlanksComplete each statement using a term or terms from the listbelow. Write your answers in the spaces provided. Some wordsmay be used more than once.mixtureliquid solutionsugar watertwoliquidsolventsolidgassolutesolublewater1. Different things close together make up a2. Ais a special kind of mixture.3. An example of a liquid solution is
15Module 2, Lesson 2Grade 7 Science4. A liquid solution hasmain parts.5. One part of a liquid solution is always a.6. The liquid part of a liquid solution is called the.7. The other part of a liquid solution can be a,or a, or a.8. The part of a liquid solution that mixes into the solvent iscalled the.9. A solute that dissolves in a solvent is said to be10. Sugar is soluble in.Part 5: MatchingMatch each term in Column A with its description in Column B.Write the correct letter in the space provided.Column AColumn B1. mixturea) means "able to dissolve"2. soluteb) liquid part of a liquid solution3. solventc) different things close together4. liquid solutiond) a special kind of mixture5. solublee) part of a solution that isdissolved
Module 2, Lesson 216Grade 7 SciencePart 6: Reaching OutBe a detective! How can you tell if a mixture is a liquidsolution? See if you can figure out the clues.Figure DFigure E This is a mixture ofsugar and water. This is a mixture ofmuddy water. Sugar and water is aliquid solution. Muddy water is not aliquid solution.Muddy Water1.A r e the p a r t s evenly mixed?2.Can you see the separate parts?3.Do particles f a l l to the bottom?4.Can y o u see clearly t h r o u g h t h i smixture?Sugar WaterHow can you tell if a mixture is a liquid solution? In your ownwords, list the clues.
Grade 7 ScienceModule 2, Lesson 217Why are Some Substances Soluble and Others Not?As you just learned, an oil and vinegar salad dressing is aheterogeneous mixture, whereas a vinegar and water mixture isa homogeneous mixture (one part dissolves into the other).To understand why this is, think back to the particle theory ofmatter. This theory states that particles are attracted to eachother. In the oil and vinegar salad dressing, oil particles have astrong attraction for only oil particles; therefore they do notspread evenly through the vinegar. However, in the vinegar andwater solution, the particles of each of the substances do nothold a strong attraction for their own particles. This allows theparticles of both substances to move between each other evenly.Learning Activity: Combining SubstancesTo complete the following learning activity, you'll need two jars,some marbles, and some sand. Fill two jars half full, one with marbles and one with sand.Predict how full the jar would be when the two substancescombine. Pour the sand into the jar of marbles. Observe what happens. Would you consider this a model of what happened whena) oil and vinegar mix, orb) when vinegar and water mix?Explain your answer.
18Module 2, Lesson 2NotesGrade 7 Science
Grade 7 ScienceModule 2, Lesson 319Lesson 3Separation Techniques and IndustryVocabulary properties magnetismLearning Outcomes filtrationAfter completing this lesson you will be able to siftingQ evaporation distillationidentify different methods of separating mixturesQj determine which method of separation would bebest for a particular circumstanceSeparation TechniquesAs discussed in Lesson 1, people sometimes want to separatepure substances from raw materials or other mixtures. In turn,these pure substances can be mixed with other substances tocreate new products or mixtures.There are a variety of ways to separate substances in mixtures.Knowing the properties — key characteristics of substances —helps to determine which method is best when separatingmixtures. Here are some options: The property of magnetism can be used to separatemixtures. For example, iron filings are attracted to magnets.If you had a mixture of iron filings and sand, you could draga magnet through the mixture to separate the twosubstances. The iron filings would become attached to themagnet, while the sand would not.
20Module 2, Lesson 3 Filtration or sifting is a method in which you use theproperty of size to separate mixtures. If the particles within amixture are two different sizes, you could use a sieve orstrainer to separate the two components. This would allowthe small pieces to fall through the sieve, while the largerpieces would be caught in the basket part. If one of thesubstances in a mixture wasmade up of small piecesand the other was aliquid, you could use filterpaper to separate the twosubstances. (This occursin the process of makingcoffee — the coffeegrounds are placed infilters and water ispoured through the filter, letting only the dissolved coffeeand water through but not the bitter, larger-sized coffeegrounds.) Evaporation is a method that you studied earlier when youthought about whether sugar would remain in a sugar-watersolution after the water had evaporated. With evaporation,the liquid portion of the solution is allowed to evaporate,leaving the solute behind. To speed up the process ofevaporation, heat can be added. Distillation is a method that uses the property of the boilingpoint to separate two components of a solution. If thecomponents do not share the same boiling point (meaning,one begins to boil at a different temperature than the other),you can separate the two by reaching the boiling point of onesubstance and having it change to a gas. Unlike straightevaporation, with distillation you can collect this gas bycooling it and having it condense into another container. Thismethod can be used to separate the components of muddywater, for example, to obtain clean drinking water.Grade 7 Science
Grade 7 ScienceModule 2, Lesson 321A Distillation UnitHere is an illustration of a distillation unit.How a Distillation Unit Works1. A solution is heated in a flask and the water turns to steam.Solids or liquids that have not reached their evaporationpoint remain in the flask.2. The steam enters the condenser and is cooled. As it cools, itchanges back to a liquid.3. The condensed liquid comes out of the condenser and entersthe receiving flask.F r o m Science Workshop Series: Chemistry Mixtures and Solutions bySeymour Rosen. 1992 by Globe Fearon, an i m p r i n t o f Pearson Learning, adivision of Pearson Education Inc. Used by permission.
22Module 2, Lesson 3Grade 7 ScienceWhat Happens in Distillation?Check with the illustration on the previous page as you read.1. The liquid solution is boiled in the boiler. The solventevaporates. The solvent changes from ato a gas (water vapor).2. The vapor moves out of the boiler. It goes into the innertube of the cooling section.3. The cold water in the outer tube cools the vapor. Thismakes the vapor condense. The vapor changes from ato a liquid.4. The liquid drips into a container. It is pure. It has beendistilled. It has no solute dissolved in it.Check This OutCrude petroleum isa fossil fuel. It isfound underground,and pumped upfrom oil wells inCanada. The crudepetroleum is thenseparated intoseveral differentsubstances, such as5. What happens to the solute? The solid solute stays behindin the boiler. It is now dried up. It is in solid form.gasoline, diesel,propane, and oillubricant. To findChromatography is a method that uses the property of theabsorption rate to separate different-coloured substancesfrom a solution. Chromatography is sometimes used toidentify solutions. Comparisons are made to the knownchromatographs of substances.For example, inks are solutions, and each type of ink has itsown characteristic chromatograph. The liquid portion of inkallows the ink to spread so that letters or drawings can bemade. When the solvent dries, you see the coloured solute leftbehind. To create a chromatograph of ink, water is allowed toabsorb and place solutes back into the solution for a briefperiod of time.out more about theprocess that is usedto separate each ofthe components ofcrude petroleum,visit: http://www.howstuffworks.com/oil-refim'ng4.htm .
Grade 7 ScienceModule 2, Lesson 323Learning Activity: ChromatographyFollow the steps below to find out what colour of pigments arein the ink of a felt pen. Make a prediction of what colours youwill see. Once you have completed the learning activity, try itagain with a different-coloured felt pen.To conduct this learning activity you'll need a clear container, acoffee filter, a pencil, tape, and two different-coloured felt inkpens.1. Cut a piece of coffee filter paper into the shape indicated onthe following diagram (like a rectangle, but with a pointedend). Your shape should be at least 11 cm long and 5 cmwide.2. Using a felt ink pen, draw a line 4 cm from the triangularend of the paper (see above).3. Attach the square end of the paper to a pencil with a piece oftape. Roll the excess filter paper onto the pencil.4. Place the tip of the paper into a container filled with 3 cm ofwater. Make sure the ink line stays above the water level.5. Observe.
24Module 2, Lesson 36. Draw a diagram illustrating your results.7. Repeat with a different-coloured felt pen.8. Compare the two results.Questions: Separation AnxietyWhich separation method — magnetism, filtration or sifting,evaporation, distillation, or chromatography — would yourecommend to divide the components of mixtures in thefollowing examples?1. A landscaping business receives a dump truck full of anunsorted mixture of sand and stones from a gravel pit. Thebusiness wishes to sort it so that bags of sand can be sold foruse in sandboxes and the small stones can be sold forlandscaping projects. What type of separation method wouldyou suggest?Grade 7 Science
Module 2, Lesson 3Grade 7 Science252. A chef is preparing stew and finds it is too watery. Withoutadding anything, how can the chef separate some of thewater from the mixture?3. A person is allergic to the yellow dying agent used inmanufacturing certain candy coatings. Although thecoatings appear as one colour, the colours are often madefrom a combination of dyes. What separation method can beused to determine if a yellow dying agent was used?Learning Activity: MatchingMatch the following terms to the appropriate ga) ability to be attracted to a magnet:b) a solute going into solution when a solvent is added:c) distinguishing characteristics of substances:d) separating parts of a mechanical mixture according to size:e) removing the solvent by exposing it to air for over a period oftime:f) technique used separate small-sized materials from a liquid:g) separating different coloured substances from a dried ink:h) method of separating a solute from a solvent that is based onthe boiling point of a substance:
26Module 2, Lesson 3NotesGrade 7 Science
Grade 7 Science Module 2, Lesson 2 15 4. A liquid solution has main parts. 5. One part of a liquid solution is always a . 6. The liquid part of a liquid solution is called the . 7. The other part of a liquid solution can be a , or a , or a . 8. The part of a liquid solution that mixes into the solvent is called the . 9.
4 Step Phonics Quiz Scores Step 1 Step 2 Step 3 Step 4 Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5 Lesson 6 Lesson 7 Lesson 8 Lesson 9 Lesson 10 Lesson 11 Lesson 12 Lesson 13 Lesson 14 Lesson 15 . Zoo zoo Zoo zoo Yoyo yoyo Yoyo yoyo You you You you
Pure substances may be elements (made up of one kind of atom) or compounds (made up of molecules containing at least two different types of atom). A pure substance cannot be physically separated into other substances, because all the particles are the same. Pure substances have fixed physical properties, such as melting and boiling point .
Pure Substances A substance that contains only one kind of particle is called a There are millions of pure substances, but only a few can be found in nature. For example, water is a pure substance, but pure water is difficult to find in nature. Even the clearest spring water contains dissolved minerals. In nature, pure substances tend to
Elements and compounds are pure substances. The composition of a pure substance is constant, and thus pure substances have characteristic physical properties that do not change. Examples of physical properties that can be used to describe pure substances include solubility, conductivi
Participant's Workbook Financial Management for Managers Institute of Child Nutrition iii Table of Contents Introduction Intro—1 Lesson 1: Financial Management Lesson 1—1 Lesson 2: Production Records Lesson 2—1 Lesson 3: Forecasting Lesson 3—1 Lesson 4: Menu Item Costs Lesson 4—1 Lesson 5: Product Screening Lesson 5—1 Lesson 6: Inventory Control Lesson 6—1
Lesson 41 Day 1 - Draft LESSON 42 - DESCRIPTIVE PARAGRAPH Lesson 42 Day 1 - Revise Lesson 42 Day 1 - Final Draft Lesson 42 - Extra Practice LESSON 43 - EXPOSITORY PARAGRAPH Lesson 43 Day 1 - Brainstorm Lesson 43 Day 1 - Organize Lesson 43 Day 1 - Draft LESSON 44 - EXPOSITORY PARAGRAPH Lesson 44 Day 1 - Revise
Classification of Matter by Composition All matter can be classified into two categories: Pure Substances or Mixtures 9. Pure Substances 10 ELEMENT. Classification of Pure Substances 11 COMPOUND. Classifying Mixtures Mixtures Homogeneous (Solutions) Heterogeneous Colloid Suspension.
Jun 13, 2017 · Heterogeneous mixtures not uniform throughout (clay-water mixture) Chapter 1 Section 2 Matter and Its . 2 Matter and Its Properties. Pure Substances A pure substance has a fixed composition. Pure substances are either compounds or elements. A pure substance differs fro
