EXPERIMENTING WITH MIXTURES, COMPOUNDS, AND ELEMENTS
Unifying Theme: All matter consists of mixtures, compounds, and elements. Unit Concept: Mixtures, compounds, and elements can be distinguished by their physical and chemical properties. Mixtures have the properties of their components and can be separated by physical means.
Compounds have properties different from those of their constituent elements and can be separated by chemical means. Elements are the basic forms of matter, have unique physical and chemical properties, and cannot be separated into other forms.
We have some ideas about pure substances and mixtures. (Lesson 1) Lesson 1- What is a pure substance and what is a mixture? o We can identify elements by their characteristic properties. o We can classify substances as either pure substances or mixtures. chemical reaction, compound, conductor, dissolve, effervescent, element, filter, insoluble, magnetic, mixture, physical change, product, reactant, reactivity, soluble
Substances can be classified as pure substances or mixtures based on their composition and behavior. (Lessons 2-5) Lesson 2- Is it a pure substance or is it a mixture? mixture, pure substance, heterogeneous, homogenous, composite
Lesson 3- How can I separate a soluble and insoluble substance? o Evaporation and filtering can be used as a separation technique o Crystals of solids may form when a solvent evaporates into a saturated solution crystal, solution, solute, solvent, filter, filtration Lesson 4- How can I separate a solute? o Chromatography can be used to analyze a mixture. o A mixture can have properties of one or more of its components or a completely different set of properties. absorption, adsorption, capillary action, chromatogram, chromatography
Lesson 5- How do the components of a mixture affect its properties? o A mixture can have properties of one or more of its components or a completely different set of properties. o Compounds have chemical and physical properties that differ from those of the elements from which they are composed. o Salt lowers the melting/freezing point and raises the boiling point o Changing the concentration of solutes affects the properties of solutions o Alloys are solid solutions with at least one metal as a principal component (the metal determines the melting point) component, mixture, freezing point, melting point, boiling point, alloy, solder
A compound has properties different from its constituent elements and can be separated only by chemical means. (Lesson 6) Lesson 6- How can I break down a compound? o Elements are pure substances that cannot be broken down o Compounds consist of two or more elements that are chemically combined o Compounds have physical and chemical properties that differ from those of the elements of which they are composed. o You can decompose a compound by passing an electric current through it. element, compound, catalyst, chemical reaction, decompose, electrodes, electrolyte, flammability
Elements can be identified by their physical appearance, chemical structure, and behavior. (Lesson 7) Lesson 7- How are the elements classified and organized? o Grouped by similarities in their physical and chemical properties o These groups are used to predict the chemical and physical properties of an element. compound, element, chemical properties, physical properties, electrical conductivity, properties, hardness, reactivity, magnetic properties, scratch test
Elements can be combined chemically to form compounds. Lesson 8- How do I create new compounds? o Elements can be classified into two major groups- metals and nonmetals o Compounds consist of two or more elements that are chemically combined o Compounds have physical and chemical properties that differ from those of the elements from which they are composed o Chemical reactions can be represented by equations element, property, metal, nonmetal, equation, product, reactant
Lesson 9- What are the characteristics of a certain compound? o Compounds have physical and chemical properties that differ from those of the elements from which they are composed o Compounds consist of two or more elements that are chemically combined chemical formula, compound, element, bibliography, rubric, compound, element, exhibit, oral presentation
Lesson 10- What are the properties of acids and bases? What is the reaction rate with metal? o Metals have different chemical properties and different reactions with oxygen. o Metals vary in their rates of reaction with acids o Different metals react at different rates with oxygen and water to corrode. o The reactivity of a metal determines how it is extracted and used. metal, nonmetal, reactivity, corrosion
Lesson 11- How can we counter corrosion? o Corrosion (rusting) is a chemical reaction with identifiable reactants and products o Oxygen and water are necessary for the corrosion of an object o Understanding the corrosion process can help prevent or reduce corrosion corrosion, control, galvanized steel Mass remains constant during chemical reactions. (Lesson 12-13)
Lesson 12- What happens to mass during phase changes? o Mass remains constant during phase changes. o The mass of reactants in a chemical reaction is identical to the mass of the products o A closed system is needed to demonstrate the conservation of mass closed system, open system, conservation of mass, products, reactants Lesson 13- What do you know about mixtures, compounds, and elements?