Science Fair

Students should observe a variety of physical and chemical changes among common substances. Examples might include: steel wool placed in copper (II) sulfate solution, oxidation of iron (rusting), ice melting, Alka-Seltzer tablet added to water, combustion of wax, vinegar added to milk, cutting of paper, toasting of bread, vinegar added to baking soda, a match burning, leaves changing colour in the fall, phenolphthalein added to sodium hydroxide, composting of organic waste, decomposition of hydrogen peroxide, etc. Students should describe the properties of each substance before and after the change for each reaction. Students should look for indicators that could provide evidence that a chemical reaction has occurred rather than a physical change. Students should be able to identify the products and reactants of each chemical reaction. Students should demonstrate safe practices throughout the investigations.

Students should describe the function of the Workplace Hazardous Materials Information System (WHMIS). This includes describing WHMIS hazard categories and symbols, and the function of Material Safety Data Sheets (MSDS). Students should also describe the Hazardous Household Product Symbols. Students should discuss why it is necessary to have national standards such as WHMIS and Canadian Standards Association (CSA). (Note: as of October 1, 2001, Health Canada only requires two frames (triangle and octagon) to indicate the degree of hazard of household products. Many current resources show a third frame (diamond) which is no longer in use.) (PSD)

Students could classify a list of chemical reactions as endothermic or exothermic, based on either written descriptions of the reactions or direct observations of the reactions. Students could suggest where or how the reaction releases or absorbs energy (e.g., a firecracker exploding releases energy as sound, light, and heat). (CCT)

Students should investigate common chemical reactions in order to identify which reactions absorb energy (endothermic) and which release energy (exothermic). Examples of materials that are simple and safe to use include: hot packs and cold packs, citric acid and sodium bicarbonate (baking soda), or vinegar and steel wool. (Note: Energy changes are a key concept in the Weather Dynamics unit, but those changes are generally due to changes of state, not chemical reactions.)

Students could generate a list of products that are used during any given day. Students could choose a product, or category of products, and research the manufacturing process, identifying the chemical reactions that occur during the process. Student responses could include an analysis of how their lives would be different without these products. Examples of categories and products for research include: auto products (brake fluid, de-icer, grease, tires), household cleaners (bleach, ammonia, fabric softener, furniture polish, glass cleaner), pesticides, pet care products (flea and tick treatment, kitty litter, fish tank cleaner), personal care products (makeup, shampoo, hair colouring, fragrances, mouthwash, toothpaste), home construction and maintenance products (glue, grout, insulation, paint, putty, stain, caulk), and arts and crafts products (fabric dye, paint thinner, epoxy glue, repositionable glue, wood filler).

Students could identify common chemical reactions that occur in Saskatchewan agriculture and industry. Examples can be found in: potash mining, fertilizer production, gold mining, oil exploration, recycling, welding, pulp and paper production, plastics manufacturing, synthetic textiles, water treatment, waste water treatment, diamond mining. It is not necessary at this point that students understand all of the reactions that take place within any of these processes, but students should recognize that chemical reactions take place throughout the agricultural and industrial sector in Saskatchewan and that these reactions are often complex. The top chemicals produced industrially in Canada are: sulphuric acid, nitrogen, oxygen, ethylene, calcium carbonate, ammonia, sodium hydroxide, propylene, and sodium carbonate.

Students could gather information about chemistry-related occupations in Saskatchewan . Research could focus on a specific sector (agriculture, mining, forestry, and manufacturing) or an occupation (technician, laboratory technologist, scientist, sales manager). Appropriate information to collect might include: the education required for these occupations, job prospects, salaries, types of skills required, job titles, numbers of positions, major employers, and locations. Students might choose to interview members of their community whose occupation requires some knowledge of chemistry. ( SaskNetWork.ca provides information specific to careers in Saskatchewan .) (CD 7.3)

Students should construct models of ionic and molecular compounds using materials such as Styrofoam balls, paper clips, marbles, marshmallows, Smarties, or commercial molecular model kits. Students could label the model to show the compound name, element(s), chemical formula, and common uses. Their models should demonstrate that the chemical formula indicates the number and type of each atom present in the compound (e.g., Al₂O₃ consists of 2 aluminum atoms and 3 oxygen atoms).

Students should write word equations for common chemical reactions based on written descriptions of the reaction (e.g., aluminum metal reacts with hydrochloric acid to form aluminum chloride and hydrogen gas can be written as aluminum + hydrochloric acid => aluminum chloride + hydrogen). Students should be able to identify the reactants and products of the chemical reaction from the word equation. (CCT)

Students should name and write formulas for common molecular compounds (e.g., CCl₄ - carbon tetrachloride, N₂O₃ - dinitrogen trioxide, etc.) using prefixes and a periodic table. Students should be able to memorize and use prefixes from 1 (mono) to 10 (deca). Students should be able to describe why the use of prefixes is essential to the naming of molecular compounds.

Students should name and write formulas for common ionic compounds using a periodic table and an ion chart. The ion chart should contain names of common simple ions (e.g., Al³⁺, Cl^-, etc.), polyatomic ions (e.g., NH₄⁺, CO₃^2- , NO₃^- , etc.), and ions that have multiple oxidation numbers (e.g., Fe²⁺, Fe³⁺, etc.). Students should be able to use the Stock system (e.g., iron (II), iron (III), etc.) for naming ionic compounds that are composed of substances that have multiple oxidation numbers. Students are not expected to use the classical system for naming ionic compounds (e.g., ferrous, ferric, etc.) or memorize lists of ions and charges. Students should be able to describe why prefixes are not required for naming ionic compounds although prefixes are required for naming molecular compounds.

Students should identify the name and chemical formula of chemical compounds that have common rather than systematic names (e.g., water, ammonia, sugar, baking soda, chalk, limewater, muriatic acid, potash, salt, bleach, battery acid, vinegar, Vitamin C, and pencil lead). Students should discuss why these substances have the names that they do and the disadvantages of using common names rather than systematic names. The term "common names" generally refers to compounds whose names were adopted before the development of formal nomenclature systems such as those developed by IUPAC. Some resources refer to these as "trivial names".

Students could research the historical development of naming systems in chemistry and identify the key contributors to the international naming systems. Students should explain how these systems have developed and why they are important as a communication tool. Students should note that there are still discrepancies among countries regarding the naming of new elements.

Students should design an experiment to determine whether mass is conserved in chemical reactions in both closed and open systems. Students should generate hypotheses, choose variables, collect appropriate data, and then conduct the experiment safely. Students should be able to explain how their data supports or refutes the Law of Conservation of Mass. Students could describe implications of the law in practical situations (e.g., wood burning, bread baking, swallowing an Alka-Seltzer, industrial processes). (NUM, TL, CCT)

Students should represent chemical reactions using word equations, chemical equations, and balanced chemical equations. Students should be able to convert a word equation into a chemical equation, convert a chemical equation into a word equation, and balance a chemical equation.

The use of physical models (e.g., Styrofoam balls, paper clips, marbles, marshmallows, Smarties, or commercial molecular model kits) to represent individual atoms in chemical reactions enables students to readily see that the numbers of atoms on each side of a balanced chemical equation must be equal. Students should practise balancing equations until students clearly demonstrate understanding that mass is conserved in chemical reactions and that atoms are neither created nor destroyed in chemical reactions.

Students should identify common organic compounds that are present in students' daily lives in order to gain an appreciation of the prevalence of organic compounds. Students could categorize these compounds according to criteria such as use (e.g., fuels, lubricants, detergents, synthetic fibres, plastics, and rubbers). Individual students or groups of students could research the uses of these and other common organic compounds.

Students could describe examples of the combustion process that students see in their daily lives (e.g., propane or natural gas BBQ, automobile gasoline, diesel fuel for a generator, butane curling iron or lighter) as well as examples which may be less readily observable (e.g., oil refinery, industrial manufacturing).

Students should observe the combustion process through the burning of hydrocarbons (e.g., a propane or natural gas BBQ, or Bunsen burner). Students should identify the reactants and products of a typical combustion reaction and the nature of energy changes during these reactions. Students should write the general word equation and a balanced chemical equation for combustion reactions in general (i.e., hydrocarbon + oxygen ® carbon dioxide + water + energy) and for specific combustion reactions (e.g., methane, propane, butane). Students should also be able to describe the origin of the energy that is released during the combustion process.

Students could construct models of common organic compounds (e.g., methane, propane, butane, octane, methanol, ethanol, and glucose) using objects such as Styrofoam balls, marbles, marshmallows, or commercial molecular model kits. As an enrichment activity, students might use the models to identify patterns in the ratios of the elements in organic compounds.

Students could research Canada 's primary hydrocarbon resources (i.e., gas and oil fields in Western Canada, the Alberta Tar Sands, and Hibernia ) and explain why these resources exist in these particular locations. Additionally, students could identify issues related to the use of fossil fuels and the advantages and disadvantages of this resource. Students could also develop a plan for alternatives to fossil fuels for public and private transportation. (IL, PSD, CCT)

Students should research the effects of the use of fossil fuels and then write a position paper, conduct a deliberative dialogue, or participate in a debate in which they defend a position related to the implications of burning fossil fuels in Saskatchewan . Students should express ideas and reactions in an appropriate manner. (IL, PSD, CD 2.3)

Enrichment: Students could research societal and environmental effects of using polymers (e.g., polyurethane, rubber, Lycra, polypropylene, polyethylene, aspartame, saccharine, linoleum) for products such as clothing, diapers, contact lenses, grocery bags, floor coverings, or artificial sweeteners.

Students could brainstorm a list of common chemical reactions and categorize them according to the rate of the reaction. Students should suggest reasons for why these reactions occur at such different rates. (COM)

Students could discuss methods of determining the rate of chemical reactions. They could suggest methods that they could use in the classroom to determine the rate of a reaction as well as methods that industry might use. Students should also be able to explain how to identify when a chemical reaction is complete.

Students could describe chemical reactions that are controlled in domestic or industrial processes (e.g., cooking, food preservation, refrigeration, explosives, pharmaceuticals, manufacturing, and air bags). Students should suggest reasons why these reactions are controlled and possible design requirements for the rate (e.g., an air bag must inflate within 15 - 20 ms after impact).

Students should design an experiment to investigate factors that may influence the rate of a chemical reaction. Typical factors to investigate include: temperature of the reactant(s), concentration of the reactant(s), surface area of the reactant(s), and the presence or absence of a catalyst. It is not necessary that each student conduct an experiment to determine the relationship of each factor. Instead, groups may investigate different factors and share the results, along with supporting documents and visuals, with classmates. Open sharing of group results helps to demonstrate the public nature of science and the need for obtaining reproducible experimental results. Students could use this set of experiments as a mini-science fair activity.

Students could investigate how to change the rate of a chemical reaction. For example, they could vary the amounts of baking soda and vinegar mixed together to simulate an explosion. Students could collect data in order to determine whether factors such as the amount of each reactant or the ratio of the reactants control the reaction rate. Students should also be able to notice a decrease in reaction rate as the reactants get used up. For an extension to this activity, consider providing students with a much larger quantity of the reactants and asking students to predict the reaction rate based on their previously graphed data. This provides an opportunity to discuss the limits of the best-fit graph specifically and the limits of extrapolation generally. (NUM)

Students could identify the role of catalysts in common chemical reactions and in industrial processes (e.g., catalytic converters in automobiles, decomposition of hydrogen peroxide, biological enzymes, manufacture of ammonia by the Haber process, the Contact process for the manufacture of sulphuric acid, and the destruction of ozone in the atmosphere). The focus of student research at this grade should be to explain how and why these processes are controlled, not to understand every step of these complex processes.

Enrichment: Students could conduct an experiment to determine whether a substance is a catalyst or a reactant in a chemical reaction.

Students should conduct an activity to determine whether common household substances are acidic or basic. Students could use a home-made indicator (e.g., boiled cabbage), litmus paper, phenolphthalein solution, pH paper, pH meter, or pH probe. A discussion of indicator technologies could highlight reasons why it is sometimes important to have very precise measurements of pH, while in other instances it may be sufficient to know that a substance is acidic or basic.

Students should develop a list of important acids and bases (e.g., sulphuric acid, lime, ammonia, phosphoric acid, sodium hydroxide), the characteristics of those chemicals, and where they might be used in Saskatchewan agriculture and industry.

Students could create a pH scale and place common substances at appropriate positions on the scale. Students should be made aware that the pH scale is logarithmic (i.e., a change of one unit on the pH scale represents a tenfold increase or decrease of hydrogen ion solution concentration). (NUM)

Students could bring samples of water (e.g., lakes, rivers, sloughs, wetlands, swimming pools, and kitchen taps) or soil (e.g., garden, school yard, compost pile, ditch, beach, sand dune) for pH testing

. Teachers could integrate this activity with objectives in the Sustainability of Ecosystems unit.

Students could design an activity to investigate one or more characteristics of acids or bases, pH, or neutralization.

For example, students might test the effectiveness of antacid tablets, test the acidity of various foods or cosmetics, or test the effectiveness of various bases in neutralizing a simulated acid spill.

Students could conduct an activity to neutralize an acid or a base. They should be able to explain what evidence supports the conclusion that water and a salt are the products of a neutralization reaction. Students should be able to discuss the role of an indicator in determining when the acid or base is neutralized.

Students could investigate practical applications of pH and neutralization by conducting research to answer questions such as:

What are natural and artificial methods of neutralizing acidified lakes?
How does lemon juice neutralize fish odors?
Why are fish only able to live in water within a certain pH range?
How is the balance of acidic or alkaline soils restored?
What is the purpose of baking soda in baking?
How do soda-acid fire extinguishers work?
How can an antacid settle an upset stomach?
Why is it important to know the pH of hair shampoos and conditioners? (IL)

Students should research a topic related to the effects of acids and bases in Saskatchewan agriculture or industry (e.g., soil chemistry, acid rain, industrial emissions, anhydrous ammonia storage and transportation). From their research, students could identify key issues and then develop a response to address all or some components of the issue. This response could take the form of a position paper, a structured controversy, a debate, a deliberative dialogue, or an action plan. Students can demonstrate giving and receiving feedback. (IL, PSD, CD 1.3)