Unit B: Matter and Chemical Change

STS and Knowledge:1. Students will investigate materials, and describe them in terms of their physical and chemical

properties.SF pp. 103-105SIA pp. 97-104

Investigate and describe properties of materials (e.g., investigate and describe melting point, solubility and conductivity of materials observed)

Chemical Properties: any property that describes how a substance reacts with another substance when forming a new substance is a chemical property.Physical Properties: any observable or measurable property without forming a new substance is a physical property.

Chemical Properties Physical PropertiesQualitative

Characteristic that may be described but not measured.

QuantitativeCharacteristic that can be measured

numerically.Reacts with water Colour Melting pointReacts with air Texture Boiling pointReacts with pure oxygen Taste DensityReacts with acids Smell ViscosityReacts with other pure substances State Solubility Toxicity Crystal shape Electrical conductivityStability Malleability Heat conductivityCombustibility DuctilityAdapted from: Table 2.2 Page 104 Science Focus 9

SF pp.95-98, 118-119, 120-125 SIA pp. 102-103

Describe and apply different ways of classifying materials based on their composition and properties, including- distinguishing between pure substances, solutions and mechanical mixtures- distinguishing between metals and non-metals- identifying and applying other methods of classification

Classification of Matter:

Matter

Pure Substances Mixtures

Elements Compounds Mechanical Solutions Suspensions Colloids Mixtures

Adapted from: Figure 2.18 Page 112 Science Focus 9

Matter: anything that occupies space (volume) and contains mass.Pure Substance: made of only one kind of matter and has a unique set of properties (chemical and physical). e.g., mercury (element) and sugar (compound).

Element: a material that cannot be broken down into any simpler substance. e.g., helium, oxygen, carbon.

Compound: when two or more elements combine chemical. e.g., water (H2O) and carbon dioxide (CO2).

Mixture: a combination of pure substances where the properties can vary depending on the quantities of the substances.

Mechanical (Heterogeneous) Mixture: a mixture in which the different substances are visible. e.g., soil

Solution (Homogeneous): a mixture in which the different substances are not visible. e.g., sugar in coffee.

Suspension: a cloudy mixture in which tiny particles of one substance are held within the other and are easily separated. e.g., tomato juice.

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Colloid: a cloudy mixture in which tiny particles of one substance are held within the other and are too small to be separated. e.g., milk

Properties of Metals, Non-metals, and Metalloids:State at Room Temperature

Appearance Conductivity (ability to transfer

thermal and electrical energy

directly)

Malleability (able to be pounded or

rolled)and Ductility (able to be stretched

into long wire)Metals Solids, except

mercury (a liquid)Shiny luster Good conductors of

heat and electricitymalleable and ductile

Non-metals Some gases, some solids, only bromine is a liquid

Not very shiny Poor conductors of heat and electricity

Brittle and non ductile

Metalloids Solids Can be shiny or dull May conduct electricity but poor conductors of heat

Brittle and non ductile

Adapted from: Table 2.3 Page 118 Science Focus 9

States of Matter

Figure 1.5 Page 97 Science in Action 9

SF pp. 99-102SIA pp.105-109

Identify conditions under which properties of a material are changed, and critically evaluate if a new substance has been produced.

Physical Change: the form of a substance is changed, but not its chemical composition. The change is temporary/reversible. E.g. ice melts to form a puddle of water, we dissolve sugar in water

Chemical Change: causes one or more new substances, with new properties, to be formed and may be difficult or impossible to reverse. e.g., burning paper.

Evidence: Heat or light energy is produced or absorbed. When gasoline burns in a car engine and heat is

released. Change in colour. Bleach on a denim jacket Change in odour. Striking a match Formation of a solid or gas (precipitate or bubbles). Vinegar and baking soda produces

bubbles.

2. Describe and interpret patterns in chemical reactions.SF pp.93-94SIA pp.93-96

Identify and evaluate dangers of caustic materials and potentially explosive reactions.

Chemicals should be handled with care at all times, especially if they are caustic (corrosive), explosive, or poisonous.

Two methods of identifying hazardous materials that can be found in school laboratories include the following:

Household Hazardous Safety Symbols:

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Page 94 Science in Action 9

Workplace Hazardous Material Information System (WHMIS):

Page 95 Science in Action 9

SF pp.118-135, 162-164SIA pp.160 and throughout

Observe and describe evidence of chemical change in reactions between familiar materials, by:- describing combustion, corrosion and other reactions involving oxygen- observing and inferring evidence of chemical reactions between familiar household

materials

Oxidation: a chemical reaction in the presence of oxygen.Corrosion: the oxidation of metals and rocks in the presence of oxygen and moisture. e.g., rust.

4Fe(s) + 3O2(g) 2Fe2O3(s) iron + oxygen iron oxide

Combustion: the highly exothermic (heat releasing) combination of a substance with oxygen resulting in the production of carbon dioxide, water, and energy. e.g., burning methane gas

CH4 + 2O2 CO2 + 2H2O + Heat methane + oxygen carbon dioxide + water + energy

SF pp.153-157SIA pp.

Distinguish between materials that react readily and those that do not (e.g., compare reactions of different metals to a dilute corrosive solution)

Test various materials (iron, copper, magnesium, nickel, etc.) using a similar solution (e.g., hydrochloric acid) to determine their reaction rates.

SF pp.149-152, 153-161, 106-109SIA pp.157-160, 166-169, 163-165

Observe and describe patterns of chemical change, by:- observing heat generated or absorbed in chemical reaction, and identifying examples of

exothermic and endothermic reactions- identifying conditions that affect rates of reactions (e.g., investigate and describe how

factors such as heat, concentration, surface area and electrical energy can affect a chemical reaction)

- identify evidence for conservation of chemical substance (e.g., identify and apply techniques for comparing the quantity of reactants and products in a chemical reaction)

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Endothermic Reactions: a chemical reaction that absorbs energy and feels cold. e.g., cold packExothermic Reactions: a chemical reaction that releases energy and feels warm. e.g., burning natural gas in a furnace. Conditions that affect the rates of reaction:

Heat: the greater the temperature the faster the reaction. e.g., banana left on a table will ripen faster than one put in the fridge.

Concentration: the greater the concentration of the substances the faster the reaction. e.g., strong vinegar will produce a faster reaction with baking soda than weak vinegar.

Surface Area: increasing the surface area of the reactants will increase the rate of reaction. e.g., crushed alka seltzer tablets will react faster than a solid tablet with water.

Catalyst: a substance that helps increase the reaction rate by lowering the amount of energy needed to make the reaction occur. Catalysts are present with the reactants but are not consumed in the reaction. e.g., enzymes speed up food digestion or electricity which lowers the activation energy.

The Law of Conservation of Mass: in a chemical change, the total mass of the new substances is always the same as the total mass of the original substance(s).

3. Describe ideas used in interpreting the chemical nature of matter, both in the past and present, and identify example evidence that has contributed to the development of these ideas

SF pp.126-135SIA pp.122-125

Demonstrate understanding of the origins of the periodic table, and relate patterns in the physical and chemical properties of elements to their positions in the periodic table---focusing on the first 18 elements

The Origin of the Periodic Table: The Periodic Table was developed by Dmitri Mendeleev to explain relationships and patterns that exist amongst

elements and their properties. He noted that there would be newly discovered elements and left space in his table. Within sixteen years those gaps were filled with elements that fit Mendeleev’s predicted pattern.

The Periodic Table Outline: Elements 1 to 36 only

Families 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 181 1 22 3 4 5 6 7 8 9 103 11 12 13 14 15 16 17 184 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Rows

Periods or Rows: the horizontal rows indicate how many electron levels, shells, or orbitals that exists in that specific element.

Groups or Families: the vertical columns indicate how many electrons exist in the last electron level, shell, or orbital of that specific element. Elements in the same groups or families share similar chemical properties. e.g., halogen gases are all in group 18.

The first two elements (hydrogen and helium) hold a maximum of two electrons in the first orbital. For elements three to eighteen (lithium to argon), electrons fill the first orbital with two electrons and

then distribute the remaining electrons in progressive orbitals, each holding a maximum of eight electrons.

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Page 120 Science in Action 9

Note: The hydrogen atom has the atomic number of 1 therefore contains 1 electron. This electron is found in the first orbital and has room to gain 1 more electron if it comes in contact with another atom. This would then completely fill the first orbital. Nitrogen’s atom has the atomic number of 7 and thus contains 7 electrons. Two of the seven electrons fill the first orbital and the remaining five occupy the second orbital. Three more electrons can be accepted into this second orbital and is only considered full once it gains these three electrons.

Electrons, Orbitals, and the Periodic Table: The period (row) that an element is found in tells us how many orbitals exist in that element. e.g.,

Hydrogen is in the first period and contains one orbital and nitrogen is in the second period and contains two orbitals.

The family (group) which an element is found indicates the number of electrons found in the last, final, or valence orbital. e.g., Hydrogen is in the first family and contains one valence electron, whereas nitrogen is found in the fifth family and contains five valence electrons.

Please note that for elements 1 to 18 the family numbers 13 to 18 needs to be explained as families 3 to 8 because we omit the transitional metals.

SF pp.112-114SIA pp.113-120

Distinguish between observation and theory, and provide examples of how models and theoretical ideas are used in explaining observations (e.g., describe how observations of electrical properties of materials led to ideas about electrons and protons; describe how observed differences in the densities of materials are explained, in part, using ideas about the mass of individual atoms)

The Scientific Method:

Observations Hypothesis Experiments Theory Time and More Experiments Revised Theory

Revised hypothesis as many times as needed.Adapted from Figure 2.18 Page 112 Science Focus 9

Laws: Describe and summarize what happens in a natural system.Theories: Imaginative ways to explain why something happens in a natural system. Models: Help picture structures or processes that cannot be directly seen.Observations: Thousands of observations must be made before the scientific community accepts theories.

History of Atomic Models:Solid Sphere or “Billiard Ball” Model: John Dalton All matter is made up of small particles called atoms that cannot be created, destroyed, or divided. All atoms of the same element are identical in mass and size. Elements can combine together in definite proportions to form compounds. Dalton’s model is basis of today’s particle theory.

Page 118 Science in Action 9

Plum Pudding Model: J.J. Thomson Negatively charged particles are embedded in a positively charged mass.

Page 119 Science in Action 9Page 5 of 12

Planetary Model: Ernest Rutherford Mass of the atom is found in the center and is called the atomic nucleus. Very small electrons occupy the remaining space of the atom.

Adapted from Figure 2.16 Page 119 Science in Action 9

Nuclear Model: Neils Bohr Electrons move around fixed pathways called electron shells.

Adapted from Figure 4.4 Page 160 and Figure 2.18 Page 120 Science in Action 9

Electron Cloud Model: Louis de Broglie Electrons have distinct electron energy levels. There is an area around the nucleus where electrons are most likely to be found called the electron cloud.

Page 120 Science in Action 9

Current Atomic Theory: Atoms are made up of a positive nucleus that contains protons and neutrons. Negative electrons orbit the nucleus in specific energy levels and occupy most of the volume of the atom. Atoms are electrically neutral because of the equal amount of protons and electrons.

Atomic Structure:Note: The Bohr model is used to diagram atomic structure.

Page 120 Science in Action 9

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Protons: positively charged particles found in the nucleus. The atomic number indicates the number of protons. Protons have 1 Atomic Mass Unit (AMU).Neutrons: neutrally charged particles found in the nucleus. Neutrons have 1 AMU. Atomic mass for an element is the sum of both protons and neutrons.Electrons: negatively charged particles found outside of the nucleus in specific orbitals. Electrons contain mass but it is so small that it is not considered in atomic mass calculations.

SF pp.127-135SIA pp.126-133

Use the periodic table to identify the number of protons, electrons and other information about each atom; and describe, in general terms, the relationship between the structure of atoms in each group and the properties of elements in that group (e.g., use the periodic table to determine that sodium has 11 electrons and protons and, on average about 12 neutrons; infer that different rows (periods) on the table reflect differences in atomic structure; interpret information on ion charges provided in some periodic tables) [Note: Knowledge of specific orbital structures for elements and group of elements is not required at this grade level]

Information found on the Periodic Table:

Adapted from Figure 2.25 Page 126-127 Science in Action 9

Atomic Number: the number of positive protons found in the nucleus of an atom. e.g., Oxygen has the atomic number of 8 therefore there are 8 protons.

Since all atoms are neutral, their positive and negative charges must be balanced. In other words, atoms contain an equal number of electrons and protons. Therefore, oxygen has 8 electrons.

Atomic Mass: the total number of protons and neutrons in an atom.Number of protons + Number of neutrons = Atomic mass

example: 8 protons + 8 neutrons = 16If you know the number of protons and the atomic mass, you can determine the number of neutrons using the following formula.

Atomic mass – Atomic number = Number of neutrons.example: 16 – 8 = 8

Ionic Charge: when neutral atoms collide, a negative electron is transferred from one atom to another, and both atoms become particles called ions, which have an electrical charge. If an atom has lost electrons the overall charge becomes positive and if it gains electrons the overall charge is negative.

Na+ means that sodium has lost one electron. O2- means that oxygen has gained two electrons.

Note: The number of protons and electrons helps determine the properties of the element.

SF pp.136-145SIA pp.144-153

Distinguish between ionic and molecular compounds, and describe the properties of some common examples of each

Ionic Compounds Molecular CompoundsBonds are created by the transfer of electrons Bonds are created by the sharing of electronHigh melting point Low melting pointDistinct crystal shape Not always form crystalsFormed from metallic and non-metallic elements Usually formed from only non-metallic elementsForms ions in solution Does not form ions in solutionConducts electricity Usually does not conduct electricitySolid at room temperature Solid, liquid, or gas at room temperature.Adapted from Table 2.4 Page 136 Science Focus 9

Diatomic Molecular Compounds: Molecules that are made of two atoms of the same element.ex: iodine (I2), hydrogen (H2), nitrogen (N2), bromine (Br2), oxygen (O2), chlorine (Cl2), and flourine (F2).

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4. Apply simplified chemical nomenclature in describing elements, compounds and chemical reactions

SF pp.136-141SIA pp.146-147, 152

Read and interpret chemical formulas for compounds of two elements, and give the IUPAC (international Union of Pure and Applied Chemistry) name and common name of these compounds (e.g., give, verbally and in writing, the name for NaCl(s) (sodium chloride), CO2(g) (carbon dioxide), MgO(s) (magnesium oxide), NH3 (nitrogen trihydride or ammonia), CH4(g) (carbon tetrahydride or methane), FeCl2(s) (iron(II) chloride)

Naming Chemical Compounds: Ionic:

1. The name includes both elements in the compound, with the name of the metallic element first.2. The non-metallic element is second. Its ending is changed to -ide

Example: CaCl2

1. calcium (M) and chlorine (NM) 2. calcium chloride (please note no prefixes are used in ionic nomenclature)

Example: Fe2O3 and FeO 1. iron (III) and oxygen 1. iron (II) and oygen 2. iron (III) oxide 2. iron (II) oxideNote: iron (III) means Fe3+ and iron (II) means Fe2+

Molecular:1. Write the entire name of the first element 2. Change the ending of the second element to –ide3. Use a prefix to indicate the number of each type of element in the formula.

mono = 1di =2tri = 3tetra = 4

Please note that mono is only used for the second element. e.g., carbon monoxide (CO)Example: CCl4

1. carbon 2. chlorine chloride 3. carbon tetrachloride

Writing Chemical Formulas: Ionic:

1. Print the metal element’s symbol with its ion charge. Next to it, print the non-metal element’s symbol with its ion charge.

2. Balance the ion charges. The positive ion charges must balance the negative ion charges.3. Write the formula by indicating how many atoms of each element are in it. Do not include the ion

charge in the formula. Place the number of atoms of each element in a subscript after the element’s symbol. If there is only one atom only the symbol is used. OR Drop and Swap the charges.

Example:1. Ca2+ and Cl1- Drop and Swap Method2. Ca 2+ = Cl1- Cl1- Ca2+ Cl1-

2+ = 2-3. CaCl2 CaCl2

Molecular:1. Write the symbols for the elements in the same order as they appear in the name.2. Use subscripts to indicate the numbers of each type of atom.

Example: 1. carbon dioxide 2. C and O2 CO2

SF pp.136-141SIA pp.140

Identify/Describe chemicals commonly found in the home, and write the chemical symbols (e.g., table salt [NaCl(s)], water [H20(l)], sodium hydroxide [NaOH(aq)] used in household cleaning supplies)

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Some common household chemical include: Baking soda NaHCO3

Salt NaCl Sugar C12H22O11

Rubbing Alcohol C3H8O

SF pp.136-139SIA pp.142

Identify examples of combining ratios/number of atom per molecule found in some common materials, and use information on ion charges to predict combining ratios in ionic compounds of two elements (e.g., identify the number of atoms per molecule signified by the chemical formulas for CO(g) and CO2(g); predict combining ratios of iron and oxygen based on information on ion charges of iron and oxygen) [Prerequisite skill: Grade 8 Mathematics, Number, Specific Outcome 15]

The Atomic Theory states that compounds are made up of atoms in definite proportions. For example;

Page 141Science in Action 9

Ions are a group of charged atoms that have lost or gained electrons. Ions combine in definite proportions. The table below shows some examples of ion charges and can be used to determine the combining ratio between two ions.

Page 146 Science in Action 9

SF pp.138, 141, 144SIA pp.148, 151

Assemble or draw simple models of molecular and ionic compounds (e.g., construct models of carbon compounds using toothpicks, peas and cubes of potato) [Note: Diagrams and models should show the relative positions of atoms. Diagrams of orbital structures are not required at this grade level.]

Model of an Ionic Compound: Model of a Molecular Compound:

Page 144 Science in Action 9 Page 141 Science in Action 9

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SF pp.146-152SIA pp.157-160

Describe familiar chemical reactions, and represent these reactions by using word equations and chemical formulas and by constructing models of reactants and products (e.g., describe combustion reactions, such as: carbon + oxygen carbon dioxide [C(s) + O2(g) CO2(g)]; describe corrosion reactions such as iron + oxygen iron(II) oxide [Fe(s) + O2(g) FeO(s)]; describe repalcement reactions such as zinc + copper(II) sulfate zinc sulfate + copper [Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s)][Note 1: This outcome does not require students to explain the formation of polyatomic ions. Some chemicals with polyatomic ions may nevertheless be introduces; e.g., a brief introduction to CuSO4(s), ZnSO4(s) and H2SO4(aq) can help prepare students for further study of these materials in units C and D][Note 2: At this grade level, students are not required to balance reactanrs and products in chemical equations. Teachers may want to inform students about opportunities for furhter study of chemistry in Science 10 and in Science 14-24]

Chemical Reactions: when two or more substances combine to form two or more new substances.Reactants: Substances that undergo the reaction or are combined in the reaction.Products: Substances that are produced in the reaction.

Types of Chemical Reactions: Formation, Composition, or Synthesis Reactions: two or more substances combine to form one new

substance.A + B AB2H2 + O2 2H2O

hydrogen and oxygen produces water (word equation) Decomposition Reactions: One substance breaks down into two or more substances.

AB A + B2NH3 N2 + 3H2

ammonia decomposes to produce nitrogen and hydrogen (word equation)

Single Replacement Reactions: A metal element switches place with a metal in a compound to form a new substance.

MB + Mp MpB + MNaCl + Li LiCl + Na

sodium chloride and lithium react to give lithium chloride and sodium Double Replacement Reactions: two metal elements switch places to form two new compounds.

MB + MpA MpB + MANaCl + LiBr LiCl + NaBr

sodium chloride and lithium bromide produce lithium chloride and sodium bromide

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Sample Exam Questions1. A substance’s ability to resist being

scratched is the physical property of matter known as….

a. ductilityb. malleabilityc. hardnessd. conductivity

2. Ductility is the physical property of…a. being able to conduct electricityb. the amount of mass in a given

volumec. being stretched into a long wired. being pounded or rolled into sheets

3. Which of the following is NOT evidence of a chemical change?

a. State changeb. Gas formationc. Color changed. Precipitate formation

4. Which of the following is a chemical change?

a. Sugar dissolved in waterb. A cooked steakc. A crushed piece of chalkd. The wax of a candle melts as the

candle burns5. To help identify substance X, Sydney the

Swashbuckler of Science listed 4 properties:a. Reacts with water to form rustb. Appears to be a shiny, silver metalc. Has a melting point of 212ºCd. Conducts electricity

How many physical and chemical properties are there?a. 1 chemical, 3 physicalb. 2 chemical, 2 physicalc. 3 chemical, 1 physicald. 0 chemical, 4 physical

6. The difference between an element and a compound is that an element…

a. is a pure substance and a compound is a mixture

b. has only one substance, while a compound has more than one substance

c. can be made into a mixture, but a compound cannot

d. can be a pure substance, while a compound cannot be a pure substance

7. A cloudy mixture in which particles of the suspended substance are so small they cannot easily be separated out is called a…

a. mechanical mixtureb. suspensionc. colloidd. solution

8. An octagon symbol means….a. Cautionb. Warningc. Dangerd. special care

9. This symbol means…

a. flammableb. corrosivec. dangerously reactived. biohazardous

10. Chemical fire starter ignites a campfire from the following reaction:2 CH3OH(l) + 3 O2(g) 2 CO2(g) + 4 H2O(l)

Methanol + Oxygen Carbon Dioxide + Water

What are the reactants?a. Methanol and waterb. Oxygen and carbon dioxidec. Methanol and oxygend. Carbon dioxide and water

11. To treat an injury in sport, cold packs are used to reduce swelling. This is an example of…

a. endothermic reactionsb. exothermic reactionsc. combustion reactionsd. corrosion reactions

12. Chewing on a tums tablet enables the reaction that occurs in our mouth and body to happen faster. This is because we have increased the…

a. surface areab. concentrationc. temperatured. work of enzymes

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13. The periodic table is organized by the patterns of the properties of the elements. The rows in the period table vary with the amount of elements they contain. These rows are called…

a. groupsb. familiesc. periodsd. metals

14. The characteristic Dimitri Mendeleev used to create the pattern we now call the periodic table is…

a. colorb. atomic numberc. atomic massd. symbol

15. John Dalton’s theory proposed that:a. atoms have a core called a nucleusb. invisible electrons were part of an

atomc. all atoms of an element have the

same mass and sized. the neutrons in an atom carry no

charge

16. Several models of what the atoms may have looked like were made. One of the earlier models, representing the atom as a positively charged sphere with negatively charged electrons embedded, was developed by:

a. Bohrb. Thompsonc. Nagaokad. Rutherford

17. The current atomic theory states that:a. protons, neutrons and electrons are

equal in massb. the mass of protons is so small that

it is not considered in atomic mass calculations

c. the atomic mass of an element is the sum of neutrons and electrons

d. positively charged particles are found in the nucleus

18. The normal ionic charge of calcium is 2+. This means that the calcium ion

a. Lost 2 protonsb. Gained 2 electronsc. Lost 2 electronsd. Gained 2 protons

19. Potassium has an atomic number of 19 and a mass of 39.10. How many neutrons does one atom of potassium contain?

a. 39b. 19c. 20d. 48

20. When ionic compounds are formed, the ions combine to form a…

a. crystalb. blockc. irregular patternd. cloud

21. Use the information in the following table to answer this question.

Compound Melting Point (ºC)

Boiling Point (ºC)

Baking soda 455 1550Carbon dioxide Sublimates -79Rubbing alcohol -90 82Salt 801 1413The molecular compounds from the table above are…

a. baking soda and saltb. rubbing alcohol and saltc. carbon dioxide and baking sodad. carbon dioxide and rubbing

alcohol

22. What is the chemical name for ZnO?a. Zinc oxygenb. Zinc (II) oxidec. Zinc oxided. Zinc oxide (II)

23. What is the common name for CaCl2?a. Sour gasb. Table salec. Limed. Road salt

24. N2O3 is a molecular compound. The chemical name is…

a. trinitrogen oxideb. dinitrogen oxidec. trinitrogen dioxided. dinitrogen trioxide

25. The chemical formula for calcium chloride is…

a. Ca2Clb. CaCl2

c. 2CaCld. Ca2Cl

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