Classification of Matter Notes Composition of Matter A. Substance—either an element or a compound 1. When all the atoms in a substance are alike, the substance is an element. 2. A compound is a substance with two or more elements combined in a fixed proportion. B. Two or more substances that can be easily separated by physical means form a mixture. 1. Heterogeneous mixture—mixture of different and easily distinguishable materials 2. Homogeneous mixture—contains two or more gaseous, liquid, or solid substances blended evenly; also called a solution 3. Colloid—heterogeneous mixture with larger particles that never settle; colloids scatter light in the Tyndall effect 4. A heterogeneous mixture containing a liquid in which visible particles settle is called a suspension. Properties of Matter A. Physical property—characteristics of a material which can be observed without changing the identity of the substances in the material; examples include color, shape, size, melting point, and boiling point 1. Appearance—physical description of a substance 2. Behavior—how a substance acts; for example, magnetism, viscosity, ductility 3. Physical properties such as size and magnetism can be used to separate mixtures. B. Physical change—change in a substance’s size, shape, or state of matter 1. Substance does not change identity when it undergoes a physical change 2. Distillation is a process for separating a mixture by evaporating a liquid and condensing its vapor. C. Chemical property—characteristics of a substance indicating that it can change chemically; for example, flammability or light sensitivity of a substance D. When one substance changes to another substance, a chemical change has occurred. 1. Some chemical changes are indicated by temperature change, smell, or bubble formation. 2. Other chemical changes occur very slowly such as the formation of rust. 3. Chemical changes can be used to separate substances such as metals from their ores. E. Weathering of Earth’s surface involves both physical and chemical changes. 1. Physical—big rocks split into smaller ones; streams carry rock particles from one location to another 2. Chemical—Chemical changes can occur in rocks when calcium carbonate in limestone changes to calcium hydrogen carbonate due to acid rain. F. Law of Conservation of Mass—Mass of all substances present before a chemical change equals the mass of all substances after the change. Content Outline for Teaching (continued) Key TermsClassification of Matter Directions: Unscramble the terms in each of the following statements. Write the term in the blanks at the left of the statements and then circle the term in the word search puzzle. 1. A(n) ethgnesuoereo mixture has different materials that can be easily distinguished. 2. A homogeneous mixture with particles so small they cannot be seen without a microscope is a(n) tuolsion. 3. A(n) ssinnopseu is a liquid heterogeneous mixture in which visible particles settle. 4. A(n) ooudnmpc is a material made from atoms of two or more combined elements. 5. If all the atoms in a sample of matter are alike, that kind of matter is a(n) neemetl. 6. A(n) oogosuenehm mixture has two or more substances blended evenly throughout. 7. The scattering of light by colloids and suspensions is called the lyTdnal effect. 8. Size, shape, and melting point are hsypialc properties 9. A burnt object has undergone a aheicmcl change. 10. The law of ionrtcvaeson of mass states that mass is not gained or lost during chemical changes. Composition of Matter Directions: Match the terms with the definitions below. Write the letter of the correct term in the blank at the left. a. Tyndall effect d. mixture g. solution b. colloid e. element h. homogeneous mixture c. heterogeneous mixture f. suspension i. compound 1. _____ heterogeneous mixture containing a liquid in which visible particles settle 2. _____ contains two or more gaseous, liquid, or solid substances blended evenly throughout the mixture. 3. _____ substance in which all atoms are alike 4. _____ any material made of two or more substances that can be physically separated 5. _____ the scattering of light by colloidal particles 6. _____ heterogeneous mixture with larger particles that never settle 7. _____ a mixture in which different materials can be easily distinguished 8. _____ homogeneous mixture of particles so small they cannot be seen and will never settle to the bottom of their container 9. _____ substance in which two or more elements are combined in a fixed proportion Properties of Matter Directions: Complete the paragraphs using the terms listed. Some terms may be used more than once. liquid physical change chemical change mixture physical properties physical property distillation equals melting conservation of mass Scientists try to explain how changes in substances take place. By applying energy, you can tear a sheet of paper into pieces and cause a 1. ____________________ ____________________ in the paper. On a hot summer day, water vapor will condense into water droplets on the outside of a glass of iced tea. The glass of iced tea is a 2. ____________________ of sugar, tea, lemon, and water. Water is a clear, colorless 3. ____________________ at room temperature. The words clear and colorless describe two 4. ____________________ ____________________ of water. The melting of the ice in iced tea is a 5. ____________________ ____________________. In comparison, a 6. ____________________ ____________________ produces new substances. When a candle burns, physical and chemical changes take place. The 7. ____________________ of the wax is a physical change. The melted wax, as it burns, combines with gaseous oxygen in air. After the chemical change, water vapor and carbon dioxide gas are formed. The mass of all substances before a chemical change 8. ____________________ the mass of all substances after a chemical change. This is called the law of 9. ____________________ ____________________ ____________________. To separate a solid from a liquid, such as salt from seawater, a process using the 10. ____________________ ____________________ of boiling point called11. ____________________ is used. Directed Reading for Content Mastery 17 Key Terms 1. heterogeneous 2. solution 3. suspension 4. compound 5. element 6. homogeneous 7. Tyndall 8. physical 9. chemical 10. conservation Composition of Matter 1. f 2. h 3. e 4. d 5. a 6. b 7. c 8. g 9. i Properties of Matter 1. physical change 2. mixture 3. liquid 4. physical properties 5. physical change 6. chemical change 7. melting 8. equals 9. law of conservation of mass 10. physical property 11. distillation