Chemical and Physical Properties & Changes PDF

Chemical and Physical Properties & Changes Science 9 Learning Goal & Success Criteria I can investigate materials and describe them in terms of their physical or chemical characteristics. I can describe changes in the properties of materials that result from some common physical and chemical reacti...

Chemical and Physical Properties & Changes Science 9 Learning Goal & Success Criteria I can investigate materials and describe them in terms of their physical or chemical characteristics. I can describe changes in the properties of materials that result from some common physical and chemical reactions. I’ll know I have it when: I can give examples and classify properties of matter as either physical or chemical. I can classify examples of physical or chemical changes. I can identify indicators of a chemical change. FLASHBACK! Recall: Last year, you looked at the properties of fluids in the Pneumatics and Hydraulics unit. Brainstorm: What were some of the characteristics of fluids? Activate Prior Knowledge; viscosity, density, temperature, freezing point, boiling point, surface tension, compressibility. Physical vs. Chemical Properties Physical Property A characteristic of a substance, that can be observed or measured without forming a new substance Chemical Property A characteristic of a substance that describes how it reacts with other substances when forming a new substance. Physical Properties of Matter ⤳Some common physical properties include colour, size, odour, hardness, density, and luster (shine). ⤳State of matter is also a physical property. Recall: solid, liquid, gas, and plasma What are some of the physical properties of an orange? 🍐 This is a Pear Deck Text Slide 🍐 To edit the type of question, go back to the "Ask Students a Question" in the Pear Deck sidebar. Physical Properties of Matter There are two major classes of physical properties; Quantitative Physical Properties Qualitative Physical Properties What does the word quantitative look similar to? What does the word qualitative look similar to? ⤳ A physical property that can be measured ⤳ A physical property that can be described, but not measured Ask students about the roots of these 2 words before providing the definitions. Quantitative looks like “quantity”. What is a quantity? Qualitative looks like “quality’. What is a quality? Qualitative Physical Properties Colour Texture Taste Smell State Crystalline structure Malleability Ductility Review with students what malleability and ductility mean as they likely haven’t heard these terms since grade 7. Quantitative Physical Properties Melting temperature Boiling temperature Viscosity Solubility Electrical conductivity Heat conductivity Density Volume Mass Students will be unfamiliar with a lot of these properties. Review with students as you address each point How many quantitative traits are being listed here? Water has some important properties, like its ability to store heat, its density of 1.00g/mL, and how it turns into a gas when it reaches its boiling point of 100 degrees Celsius. These properties help control our climate, keep temperatures stable in lakes and oceans, and play a big role in science and everyday activities. 🍐 This is a Pear Deck Number Slide 🍐 To edit the type of question, go back to the "Ask Students a Question" in the Pear Deck sidebar. Which of the following options is not a qualitative physical property of orange juice listed here? Orange juice is usually a bright, orange color and tastes sweet and tangy. It smells fresh and citrusy, and some kinds have bits of pulp in them. It can look clear or a bit cloudy, and the taste might vary from brand to brand. Orange juice is acidic with a pH of 4.2. 🍐 This is a Pear Deck Multiple Choice Slide. Your current options are: A: colour, B: taste, C: pH, D: smell, 🍐 To edit the type of question or choices, go back to the "Ask Students a Question" in the Pear Deck sidebar. Physical vs. Chemical Properties Physical Property A characteristic of a substance, that can be observed or measured without forming a new substance Chemical Property A characteristic of a substance that describes how it reacts with other substances when forming a new substance. Chemical Properties of Matter Some examples include: Reacts with water Reacts with air Reacts with acids Reacts with oxygen Reacts with pure substances Toxicity Stability Combustibility Acidity What do a lot of these properties have in common? What are some chemical properties of vinegar (acetic acid)? It’s okay if these are harder to come up with! 🍐 This is a Pear Deck Text Slide 🍐 To edit the type of question, go back to the "Ask Students a Question" in the Pear Deck sidebar. Why is one a physical change and the other a chemical one? Image from Chem4Kids Click for more info! Liquid H2O → Solid H2O H2O2 → H2O + H2 Image from: http://www.chem4kids.com/files/matter_chemphys.html During a physical change, no new substance is formed. New properties may appear, but the chemical composition of the starting material remains unchanged. Examples may include: Changes in state (melting, solidifying, sublimating, evaporating, condensing) Breaking Changes in size or shape Dissolving a solute into a solvent Physical Changes Ask students if they can think of any other examples. Chemical Changes A chemical change is a change in matter in which at least one new substance, with new properties, is formed occurs when bonds between atoms either break or form creating a new substance. 4Fe + 3O2 → 2Fe2O3 Image also from http://www.chem4kids.com/files/matter_chemphys.html Indicators of a Chemical Change The following indicators are evidence (not proof) of a chemical change: Heat is produced or absorbed The starting material is used up A new colour appears A light is produced A starting colour disappears A material with new chemical properties forms Gas bubbles form in a liquid Grains of solid precipitate form in a liquid Ask students if they can think of any other examples? Students may say change in smell (burning smell or cooking smell). Indicators of a Chemical Change A precipitate is an insoluble substance formed as a result of a chemical change when two soluble substances react Precipitate forming Lead iodide forms, which is insoluble in water. It precipitates as a yellow solid. What indicators of a chemical change do you observe in this video? https://www.youtube.com/watch?v=66kuhJkQCVM 2 More Definitions Combustibility: the ability of a substance to burn in the presence of Oxygen, giving off heat and light in the process. Combustion results in a chemical change. Density: The amount of mass in a given volume. Often expressed in units of grams/milliliter (g/ml) or kilograms per litre (kg/L) Helpful Videos Physical vs Chemical Properties Physical vs Chemical Changes To Do: Complete the following, all related to physical & chemical properties and changes: 2.1 (notes sheet, using the slides) 2.2 - classwork #1 (Google Doc assignment) - Due Tomorrow 2.3 classwork #2 (Google Slides assignment) -