Chemical Reactions Students use the scientific method to explore a set of chemical reactions and discover how organisms use chemistry to survive. Grade Level: 6th Next Generation Science Excellence in Environmental Standards Education Guidelines Phenomena: By conducting experiments, we MS-PS1-2. Strand 1— Questioning, Analysis can observe different types of Analyze and interpret data on the and Interpretation properties of substances before and A) Learners are able to develop, reactions and how they relate to after the substances interact to focus, and explain questions that nature. determine if a chemical reaction has help them learn about the occurred. environment and do Objectives: environmental investigations. Students will list three ways Science and Engineering that living things use chemical Practices (SEP): B) Learners are able to design reactions Analyzing and Interpreting Data environmental investigations to Students will explain how to tell answer particular questions— whether a chemical reaction Disciplinary Core Ideas: often their own questions. has occurred. Structure and Properties of Matter C) Learners are able to locate and Materials: Crosscutting Concepts collect reliable information about A glow stick for each group Patterns the environment or environmental topics using a Paper cups, popsicle sticks, variety of methods and sources. plastic spoon, glue, borax Clear cups or beakers, pH G) Learners are able to synthesize strips, baking soda, vinegar their observations and findings Steel wool, vinegar, glass jar, into coherent explanations. thermometer Laminated instruction sheets for each station Organisms like fireflies and Worksheets - if the students Background don’t keep notebooks angler fish use a reaction Chemistry is an extremely known as bioluminescence to Appendixes: versatile science that can be attract mates or prey. This Station instructions: Page 5 used to make everything from reaction occurs when a Reaction action worksheet: Page 6 pharmaceuticals to athletic chemical in the organism Station and reaction key: Page shoes. Without chemistry we’d called luciferin combines with 7 have no gasoline, plastics or oxygen and gives off energy in preservatives. the form of light. Other Time Considerations: Preparations: 45 minutes organisms including jellyfish Lesson Time: 50-55 minutes While it is essential to today’s and some algae and fungi are Introduction: 5 minutes Activity 1: 40 minutes society, chemistry is the basis also bioluminescent, but for Conclusion: 5-10 minutes for nearly all biological unknown reasons. processes. Chemical Related Lesson Plans: interactions are responsible for These organisms give off light photosynthesis, digestion and like an activated glow stick as basic cellular functions. In the result of a chemical addition to these primary reaction. Some insects and functions, some living things plants will glow under UV also use chemistry for survival. radiation or blacklight. This is 1 Other natural chemicals make even erode buildings! Biologists stink bugs smell bad and certain use special tools called pH plants taste bitter. Some meters or chemicals called pH organisms make poisonous indicators to track the acidity of chemicals for protection or to kill lakes and streams. their prey. Others animals borrow chemicals from other In many biological processes, organisms. Reindeer keep their molecules must be taken apart cells healthy by eating mosses to form new molecules. When that have a chemical that acts the bonds holding atoms in the as a natural antifreeze. molecule are broken, energy is often released in the form of This fish uses bioluminescence to lure prey Humans often impact the heat. When more heat is toward its mouth. chemistry of the environment by released than it takes to break adding more chemicals to the up the molecules, the processes not the same process as mix. Sometimes this is helpful is called exothermic. When bioluminescence and it is not like when we use fertilizer or chemical reactions take in heat caused by a chemical reaction. pesticides to grow healthy instead, they are called Instead, the energy emitted by crops. However too much of endothermic. Exothermic the UV light is absorbed by these chemicals can be bad for reactions feel warm while electrons in some molecules the ecosystem and make the endothermic reactions feel cold. and re-emitted as light. animals sick. Extra fertilizer can Preparation Depending on how long light is cause something called algae emitted, this process is called bloom where algae populations Prepare a borax solution by either fluorescence or grow out of control and adding powdered borax to water phosphorescence (Haddock, suffocate other aquatic until it will no longer dissolve. S.H.D.). organisms. Prepare the baking soda solution by combining two Spiders and silkworms use Another way humans affect tablespoons of baking soda and chemistry to make their webs Earth’s chemistry is by adding four cups of water. Gather all and cocoons through carbon to the atmosphere. lesson materials and set up the polymerization reactions. A When gasses like carbon stations prior to the lesson. single silk molecule is called a dioxide mix with water in the monomer. When the atmosphere they form acids that Introduction: polymerization reaction occurs, can hurt plants and animals or Ask the class what a chemical these monomers link up like reaction is. Explain that a paperclips to form large strings chemical reaction is an or blobs called polymers. The interaction between substances properties of the polymer that makes or destroys depend on the molecules molecules. involved and how they are connected. Manmade polymers include rubber, nylon and Doing the Activity polyester (Ontario Educational In physical reactions, the Communications Authority). molecules and chemical Spiders make their webs from proteins linked properties of the substance together by a polymerization reaction. 2 don’t change. Cutting your grass (The Science House). or smashing a vase are physical Station 1: Bioluminescence changes. So are melting, boiling Materials: 1 glow stick Compare the glue to the ending and freezing. material and write down any Students should examine the other observations. Ask the students if they know glow stick before activating it. any of the signs that a chemical What kind of natural reactions reaction has happened. (light Write any observations or could this be related to? (This emitted, temperature, color or questions and draw and label a reaction sticks long molecule odor change, bubbles, new picture of the glow stick. chains called polymers together. “stuff” is made) List these Activate the glow stick and write Spiders, silkworms and indicators on the board for down any observations or caterpillars all make polymers to student reference. questions. build their webs or cocoons.) Tell the students that they will Answer these questions: Station 3: Color Change be examining some chemical How do glow sticks work? Materials: clear cup or beaker, reactions today that relate to (They are made of two tubes pipette, baking soda solution, reactions found in nature. each containing different pH strips, vinegar chemicals. When the inner tube Activity 1: Reaction Stations is broken and the chemicals Pour about 1/2 inch of baking Explain each station to the mix, a reaction occurs that gives soda solution into the cup. students and remind them of off energy in the form of light.) Measure the pH by dipping a pH important safety procedures: strip in the liquid and noting do not put anything in your Are there similar reactions in what color the strip is. mouth, try not to get anything on nature? If so, where? your skin or clothes, no (Yes. Fireflies, fish, plants, Using the pipette, slowly add horseplay. bacteria and fungi all perform vinegar to the solution and write similar chemical reactions called your observations. Split the class into groups of no bioluminescence.) more than three students and Why do bubbles form? Why send them to a station. If a Station 2: Polymers does the solution change color? group’s first station is a writing *Place two groups at this station Vinegar is an acid and baking station, they should be working instead of having a soda is a base; how do you on the physical or chemical corresponding writing station think the pH changes when you worksheet. mix them together? (The Materials: paper cup, popsicle reaction between baking soda Half of the stations will give stick, glue, borax solution, and vinegar produces carbon students the chance to write on plastic spoons dioxide. The color change their worksheets or in their comes from an indicator solution science notebooks. The Put two spoonfuls of glue into when the acid and base are experiments will be completed the empty cup. Using the clean neutralized.) at the other stations. Stations spoon add two spoons of borax last five minutes. solution to the glue. Why is pH important to life on Earth? (Organisms need a Note that materials listed are per Count to three and stir the specific pH to survive because it group. mixture with a popsicle stick 3 impacts the chemistry of their Ask the students to list some Vocabulary bodies.) signs that a chemical reaction Acid: sour substance which reacts has happened. with bases to form a salt and has a pH Station 4: Temperature less than seven Change Base: bitter substance which reacts Materials: glass container, steel Assessment with acids to form a salt and has a pH wool, vinegar, thermometer greater than seven Use the students’ journals or Bioluminescence: the emission of Measure the temperature inside worksheets and discussion light from living organisms caused by a biochemical reaction the jar and write it down. responses to assess their Soak a piece of steel wool in learning. Endothermic: taking in heat vinegar for 1 minute. Squeeze Exothermic: giving off heat out the extra vinegar, wrap the steel wool around the base of Extensions Hypothesis: a temporary prediction the thermometer and place in that can be tested about how a scientific investigation or experiment jar.