Roselle School District

Grade 7 Honors Science Curriculum

Unit 2 – Physical Science – Matter & Energy

Essential Question(s) / Enduring Understanding(s)
How do the properties of materials determine their use?
How does conservation of mass apply to the interaction of materials in a closed system? / The structures of materials determine their properties.
When materials interact within a closed system, the total mass of the system remains the same, which is known as the Law of Conservation of Mass.
Science Standards, 2009
5.1 Science Practices: All students will understand that science is both a body of knowledge and an evidence-based, model-building enterprise that continually extends, refines, and revises knowledge. The four Science Practices strands encompass the knowledge and reasoning skills that s A. Understand Scientific Explanations: Students understand core concepts and principles of science and use measurement and observation tools to assist in categorizing, representing, and interpreting the natural and designed world. Students must acquire to be proficient in science.
B. Generate Scientific Evidence Through Active Investigations: Students master the conceptual, mathematical, physical, and computational tools that need to be applied when constructing and evaluating claims.
C. Reflect on Scientific Knowledge: Scientific knowledge builds on itself over time.
D. Participate Productively in Science: The growth of scientific knowledge involves critique and communication, which are social practices that are governed by a core set of values and norms.
5.2 Physical Science: All students will understand that physical science principles, including fundamental ideas about matter, energy, and motion.
A. Properties of Matter: All objects and substances in the natural world are composed of matter. Matter has two fundamental properties: matter takes up space, and matter has inertia ion, are powerful conceptual tools for making sense of phenomena in physical, living, and Earth systems science.
B. Changes in Matter: Substances can undergo physical or chemical changes to form new substances. Each change involves energy.
Language Arts Standards:
RST.6-8.1. Cite specific textual evidence to support analysis of science and technical texts.
RST.6-8.3. Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.
RST.6-8.4. Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant togrades 6–8 texts and topics.
RST.6-8.2. Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions.
RST.6-8.9. Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic.
RST.6-8.7. Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table).
W.7.2 Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.
W.7.2a Introduce a topic clearly, previewing what is to follow; organize ideas, concepts, and information, using strategies such as definition, classification, comparison/contrast, and cause/effect; include formatting (e.g., headings), graphics (e.g., charts, tables), and multimedia when useful to aiding comprehension.
W.7.2b Develop the topic with relevant facts, definitions, concrete details, quotations, or other information and examples.
W.7.2c Use appropriate transitions to create cohesion and clarify the relationships among ideas and concepts.
W.7.2d Use precise language and domain-specific vocabulary to inform about or explain the topic.
W.7.2e Establish and maintain a formal style.
W.7.2f Provide a concluding statement or section that follows from and supports the information or explanation presented.
Learning Expectations
TLWBAT… / Activities/Resources / Student Strategies / Formative Assessments / Technology
Integration
Explain that substances can be pure or mixed and identify heterogeneous and homogenous mixtures when presented with different scenarios
Compare and contrast heterogeneous and homogenous mixtures
Identify chemical and physical changes
Compare and contrast chemical and physical changes in order to explain the difference between chemical and physical changes
Identify signs of a chemical change
Justify that a chemical change has taken place with specific evidence from experimentation
Determine whether a reaction is endothermic or exothermic and provide explanation supporting conclusion (honors only)
Identify factors that impact reaction rate
Explain the impact temperature has upon reaction rate
Evaluate the impact of surface area upon reaction rates as well as the combined impact of surface area and increased temperature(Honors only)
To name compounds based upon the elements that comprise the compounds with specific attention being paid to the ratio of elements within the compound
To identify valence electrons of an element based upon its location on the periodic table
To analyze trends in the periodic table to predict the number of valence electrons available for bonding
To differentiate between the different types of chemical bonds connecting valence electrons and Lewis structures to bonding / Have students watch the Brainpop video Compounds and Mixtures and take the graded quiz as a preview to the lesson: http://www.brainpop.com/science/matterandchemistry/compoundsandmixtures/
Inquiry Activity: What happens when substances are mixed?
Materials: water, cornstarch, clear plastic cup, spoon
Procedure: Observe and describe the water and the cornstarch. Students can touch the corn starch, if they would like to add into their description of the substance how it feels.
Next, have students add a teaspoon of corn starch to the water in the cup and stir with the spoon. Have students observe and describe their results of mixing the water and cornstarch together being as descriptive as possible. (Allow students to touch the cornstarch and water mixture if they’d like to.)
Analysis: After you mixed the substances together, could you still see each substance? Explain your answer. How did the new substance differ from the original substance? Explain your answer.
Debriefing: After the two substances were mixed, you could not see each substance; the new substance had a consistency different from that of either substance alone.
Inquiry Activity: Heterogeneous and Homogenous Mixtures (Honors only)
Materials: Cocoa Puffs cereal, Froot Loops cereal, plastic bowls and spoons, milk
Procedure: Have students measure ½ cup of Cocoa Puffs cereal and place it in the plastic bowl. Have students measure 1/3 cup of milk and add it to the cereal in the bowl. Now, have students take a spoon full of cereal and milk and examine it. Have students describe the contents of the spoon. Have students repeat the same procedure three times of retrieving a spoon full of the bowl’s contents and examining and describing the contents.
Next, have students follow the same procedure with the Froot Loops cereal. Have students be specific in their descriptions of the contents of the spoon for each trial.
Analysis: How did the contents of your spoons differ for the different types of cereal?
Debriefing: Explain to students that the Cocoa Puffs and milk mixture was a homogenous mixture because no matter how many times you took a scoop of the mixture you would always get Cocoa Puffs and milk ( a homogeneous mixture because it was always chocolate cereal and milk), but when you used the Froot Loops cereal, you would get all the different flavors of Froot Loops or you could get a scoop where not all the different flavors were present and that mixture was a heterogeneous mixture; that it was not the same throughout the mixture.
Inquiry Activity: Mixtures Activity
Question: How does a mixture differ from a compound?
Materials: lemon juice, water, cooking oil, chocolate syrup, milk, plastic cups, spoons
Procedure: Fill a plastic cup half way with water. Add a few drops of lemon juice to the cup and stir.
Record your observations.
Next, add four teaspoons of oil to the cup with the water and lemon juice. What happens? Record your observations.
In a separate cup, fill the cup one-third of the way with milk and stir in one spoon of chocolate syrup and stir. Record your observations.
Now, add a few drops of lemon juice to the cup with the milk and syrup. What happens? Record your observations.
Analysis:
What is the difference between the cup with the lemon juice and water and the cup with the lemon juice, water and oil? Explain your answer using scientific vocabulary related to mixtures.
What did you create when you added the lemon juice to the milk and chocolate syrup? Explain your answer using scientific vocabulary related to mixtures.
How is the cup with the lemon juice, water and oil similar to the cup with the milk, chocolate syrup and lemon juice?
Compare and contrast heterogeneous and homogeneous mixtures. Be sure to use scientific vocabulary from the unit and examples from this activity in your response.
Debriefing:
Be sure that students grasp the concept of homogeneous and heterogeneous mixtures pointing out that the lemon juice and water mixture became cloudy and that the entire mixture is cloudy throughout; therefore, the mixture is a homogenous mixture. Once the oil is added, the mixture is no longer homogeneous because it is not the same throughout and that students created a heterogeneous mixture. Have students draw the same conclusion with regard to the milk and chocolate syrup as a homogenous mixture and once the lemon juice is added, the mixture becomes heterogeneous and is no longer the same throughout.
Introduce physical change and chemical change with teacher demonstration of alcohol burning in a beaker and breaking of a piece of clay into smaller pieces. Have students explain some physical properties of an object within the classroom and then write their own definition of what a physical property is. Explain that physical changes are just changes of state. Have students demonstrate a physical change using an everyday item and explain why the change was a physical change, what state change occurred.
Have students reshape clay to demonstrate physical changes or tear paper into smaller pieces or have an ice cube melt on a plate. (Inquiry activity: Clay)
Have students take the chemical and physical changes quiz on the link below: http://www.quia.com/quiz/303980.html?AP_rand=397917796
Inquiry Activity: Investigating Chemical and Physical Changes (30 mins.)
Question: What are some signs of a chemical change and a physical change?
Procedure:
1.  Fill cup #1 with water about one-quarter of the way full.
2.  Add an Alka Seltzer tablet to the cup and record your observations below.
3.  Fill cup #2 with vinegar about one-quarter of the way full.
4.  Add a Vitamin C tablet to cup #2 and record your observations below.
5.  Answer the questions in the analysis section.
Observations: (Remember to record your observations in COMPLETE sentences.)
Cup #1
Cup #2
Analysis:
1.  What type of change, if any, did you observe in the first cup, a physical change or a chemical change? Explain your answer.
2.  What type of change, if any, did you observe in the second cup? Explain your answer.
3.  Do you think that chemical changes occurred? Why or why not? Explain your answer.
4.  What are some characteristics of chemical changes?
Explain how chemical properties describe how substances can form new substances. Give examples from students’ daily life: a fence rusting or wood burning.
Teacher-created Power Point Presentation: Review signs of chemical change with students: production of an odor, change in temperature change in color, formation of bubbles to depict a gas, and formation of a solid (a precipitate).
Have students write an explanatory essay comparing and contrasting physical and chemical changes with at least two compositional risk and effective use of transitions after completing and reviewing a Venn diagram to support the writing process (Honors only)
Teacher demonstration the “elephant toothpaste” experiment to “feel” firsthand the temperature changes with the release of heat from the reaction. Have students explain whether the reaction was an endothermic or an exothermic reaction and why. (Honors only)
Inquiry Activity: Feel an Endothermic Reaction (Honors only)
Mix Citric Acid solution in a plastic cup with baking soda solution
Allow kids to place two fingers into the cup to feel the reaction. They should feel it bubble more vigorously and their fingers should feel cold after a bit.
Ask them to describe what they feel/felt. See if they can explain where the heat in their fingers is going.
Debriefing: When you put your fingers in the solution, it will bubble and speed up because you're giving the acid and the base mixture the heat energy it needs to get going and keep going. Also, it's taking the heat from your fingers so your fingers will feel cold in the solution and when you remove them.
Inquiry Activity: Carbon Dioxide (30 mins.) (Honors only)
Materials: Ziploc baggies, baking soda, vinegar, plastic eye dropper
Procedure:
Put 1 teaspoon of baking soda into the baggie and zip it closed. Shake the baggies so the baking soda settles to one corner of the bag.
Fill the eye dropper with vinegar but do not squeeze it out.
Open the baggie and gently place the full eye dropper into the baggie with the opening facing the baking soda.
Gently pat the baggie to get out as much air as possible and then seal the baggie.
Squeeze the eye dropper to allow the vinegar to react with the baking soda.
Record your observations.
Wait two to three minutes and then feel the baggie and record your observations.
Analysis:
Did a chemical reaction occur? If so, what evidence do you have that a reaction occurred?
If a reaction occurred, was it an endothermic or an exothermic reaction and how do you know?
Debriefing:
The students will see bubbles and hear a fizzing sound right away. After a while, they should notice that the bag has inflated and that the contents feel cold evidence of an endothermic reaction.
Inquiry Activity: Oxygen (30 mins.) Honors only)
Materials: yeast, Ziploc baggies, plastic eye droppers, hydrogen peroxide, measuring spoons
Procedure:
Put ¼ teaspoon of yeast into a baggie and close the baggies. Shake the baggie so that all the yeast settles into one corner.
Fill the eye dropper with hydrogen peroxide. Do not squeeze it out!
Place the full eye dropper into the baggie with the opening facing the yeast.
Gently pat the baggie to get out as much air as possible.
Squeeze the eye dropper and record your observations.
Wait two to three minutes and then feel the baggie and record your observations.