Lesson 1 Substances and Mixtures

Transcription

1 Lesson 1 Student Labs and Activities Page Launch Lab 8 Content Vocabulary 9 Lesson Outline 10 MiniLab 12 Content Practice A 13 Content Practice B 14 School to Home 15 Key Concept Builders 16 Enrichment 20 Challenge 21 Matter and Atoms 7

2 Launch Lab LESSON 1: 10 minutes Can you always see the parts of materials? If you eat a pizza, you can see the cheese, the pepperoni, and the other parts it is made from. Can you always see the individual parts when you mix materials? Procedure 1. Read and complete a lab safety form. 2. Observe the materials at the eight stations your teacher has set up. 3. Record in the Data and Observations section below the name and a short description of each material. Data and Observations Think About This 1. Classify Which materials have easily identifiable parts? 2. Key Concept Is it always easy to see the parts of materials that are mixed? Explain. 8 Matter and Atoms

3 Content Vocabulary LESSON 1 Directions: Explain the differences between the terms in each pair on the lines provided. Use complete sentences. 1. heterogeneous mixture; homogenous mixture 2. atom; element 3. element; compound 4. substance; mixture 5. molecule; atom 6. compound; molecule 7. individual; multiple 8. chemical change; physical change 9. matter; substance Matter and Atoms 9

4 Lesson Outline LESSON 1 A. What is matter? 1. Anything that has mass and takes up space is considered to be. 2. Types of, including heat, sound, and electricity, and such as magnetism and gravity are not matter. B. What is matter made of? 1. The building blocks of matter are small particles called. 2. The different ways that atoms combine with each other help us identify different types of. C. Classifying Matter 1. Scientists classify all matter into two main groups: and. 2. The difference between the two main kinds of matter is their. D. What is a substance? 1. Matter with a composition that is always the same is a(n). 2. A substance made up on only one kind of atom, such as gold is a(n). a. Some elements are formed of, which are units formed of two or more atoms that are held together by chemical bonds. b. There are about 115 elements, each of which has its own chemical. 3. A(n) is a substance made up of two or more elements that are chemically joined in a specific combination; most matter is formed of. E. What is a mixture? 1. Matter that can vary in its composition is a(n). 2. The substances that make up are not bonded together. 10 Matter and Atoms

5 Lesson Outline continued F. Types of Mixtures 1. Mixtures differ in how the substances that form them are mixed. 2. A mixture, such as trail mix, in which the substances are not evenly mixed is a(n) mixture. 3. A mixture in which two or more substances are evenly mixed, but not bonded together is a(n) a(n). mixture, also called 4. All three states of matter can be a(n) or a solvent in a solution. G. Compounds v. Mixtures 1. The parts of any kind of, including trail mix, soda, and air, keep their properties. 2. The atoms that make up a(n) are bonded together, so its composition is always the same. 3. The substances that make up a(n) are not bonded together, so adding more of one substance in a solution will not change the composition of the solution. 4. You can separate the parts of any mixture by using processes. a. A(n), a strainer, or a ladle can be used to separate the parts of a(n) mixture. b. The best methods for separating a(n) mixture a solution is to use or evaporation. H. Visualizing Classification of Matter 1. Matter can be classified as a(n) or a(n). 2. A substance can be classified as a(n) or a(n). 3. A mixture can be classified as or. 4. All the matter in every category is made up of. Matter and Atoms 11

6 MiniLab LESSON 1: 20 minutes How do elements, compounds, and mixtures differ? The elements in a compound cannot be separated easily. However, you often can use the properties of the substances in a mixture to separate them. Procedure 1. Read and complete a lab safety form. 2. Observe samples of sand and iron filings with a magnifying lens. Record your observations in the Data and Observations section below. 3. Combine the sand and iron filings in a clear cup. Stir with a toothpick. Observe the mixture with the magnifying lens. Record your observations. 4. Cover one end of a magnet with plastic wrap. Stir the mixture with the covered magnet. Record your observations. Data and Observations Analyze and Conclude 1. Classify The formula for sand is SiO 2. The symbol for iron is Fe. Use this to classify each as an element, a compound, or a mixture. 2. Key Concept What are two ways you could tell from your observations that the combination of sand and iron filings is a mixture and not a substance? 12 Matter and Atoms

7 Content Practice A LESSON 1 Directions: Use the clues to complete the crossword puzzle Clues Across 1. a mixture in which two or more substances are evenly mixed but not bonded together 6. a mixture in which the substances are not evenly mixed 7. two or more atoms that are held together by chemical bonds and act as a unit 8. matter with a composition that is always the same Down 2. anything that has mass and takes up space 3. substance made of only one kind of atom 4. a small particle that is the building block of matter 5. substance made of two or more elements that are chemically joined in a specific combination Matter and Atoms 13

8 Content Practice B LESSON 1 Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided. 1. Gravity is matter because it does not have mass and volume. 2. Each type of atom has a different number of smaller particles. 3. The composition of a substance is always the same. 4. The substances in a mixture are bonded together. 5. All atoms of an element are alike. 6. The atoms in a molecule are held together by chemical bonds. 7. Elements can be classified as metals, nonmetals, and metalloids. 8. Compounds are made of atoms of the same element bonded together. 9. Soda is an example of a heterogeneous mixture, or a mixture in which two or more substances are evenly mixed but not bonded together. 14 Matter and Atoms

9 School to Home LESSON 1 Directions: Use your textbook to complete the activity. Use the word bank below to complete the concept map describing how matter is classified. compounds elements heterogeneous mixtures homogeneous mixtures mixtures substance Matter can be classified as a. b. which are made up of only one kind of atom. which can be c. d. which are two or more kinds of atoms chemically joined in specific combinations. in which which can be e. f. the components are not evenly mixed. in which two or more components are evenly mixed but not bonded. Matter and Atoms 15

10 Key Concept Builder LESSON 1 Key Concept What is the relationship among atoms, elements, and compounds? Directions: Answer each question or respond to each statement in the space provided. 1. What is an atom? 2. What happens when atoms combine? 3. What is an element? 4. Name three elements. 5. What is the relationship among atoms, elements, and molecules? 6. What is a compound? 7. Name three compounds. 8. What information about a compound is found in its chemical formula? 9. How are atoms related to elements and compounds? 16 Matter and Atoms

11 Key Concept Builder LESSON 1 Key Concept How are some mixtures different from solutions? Directions: On the line before each item, write HE if the item represents a heterogeneous mixture or HO if the item represents a homogeneous mixture. 1. granite 2. smoke 3. soda 4. brass 5. trail mix 6. air 7. tap water Directions: Answer each question on the lines provided. 8. What is the difference between a heterogeneous mixture and a homogeneous mixture? 9. Which mixtures listed in the activity above are solutions? Explain your answer. Matter and Atoms 17

12 Key Concept Builder LESSON 1 Key Concept How do mixtures and compounds differ? Directions: Complete the chart by writing the correct term from the word bank on the lines provided. Some terms may be used more than once or not at all. atoms compounds elements heterogeneous mixture homogeneous mixture mass matter mixtures substances Matter anything that has (1.) and takes up space most made of (2.) two classifications: (3.) and (4.) (5.) made up of one or more types of atoms in the same combinations two types: (6.) and (7.) (8.) made of only one type of atom organized on the periodic table have a chemical symbol (10.) made of two or more (11.) Combinations of subtances can vary. two types: (12.) and (13.) (14.) two or more substances unevenly mixed different substances visible by unaided eye or microscope (9.) made of two or more types of atoms bonded together properties are different from the elements that make it up have chemical formulas that are not bonded together (15.) two or more substances evenly mixed Different substances cannot be seen by a microscope. 18 Matter and Atoms

13 Key Concept Builder LESSON 1 Key Concept How do mixtures and compounds differ? Directions: Put a check mark on the line before each property that is typical of a compound. 1. made of only one kind of atom 2. made of unbonded substances 3. is a substance 4. made of elements that are bonded together 5. represented by a chemical formula 6. Identity is not changed by changing the amount of its substances. 7. is the smallest part of an element 8. is often made of molecules Directions: Respond to each statement on the lines provided. 9. Compare the composition of a mixture and a compound. 10. Compare what happens when you change the composition of a mixture and a compound. Matter and Atoms 19

14 Enrichment LESSON 1 Categorizing Mixtures You have learned that a mixture can be heterogeneous or homogenous. Mixtures are also classified based on the size and distribution of the solute particles. Aerosol cans are often used to apply paint to small surfaces. The gas in the can is under pressure. When you press the button, the gas escapes, carrying droplets of paint outward. Suspensions In a suspension, one substance is finely divided and temporarily suspended throughout another substance. Particles in a suspension are often large enough to see. The substances can be mixed by shaking, but the dispersed substance eventually settles out because of the particle size. Common suspensions include sand in water or Italian salad dressing. Because of their size, particles of a suspension can often be separated through a filter. For example, you could use filter paper to separate the solids from the liquids in salad dressing. People use filters on a furnace to clean the dust particles from air and prevent them from settling on surfaces around the house. A suspension of liquid droplets or fine solid particles in a gas is called an aerosol. In the atmosphere, these consist of fine dust and soot particles that appear as haze, smog, or air pollution. Applying Critical-Thinking Skills Directions: Answer each question. Colloids A colloid is a permanent suspension. The particles of the suspended substance are larger than particles in a solution but smaller than those in a suspension. Because they are so tiny, they don t settle out. They remain suspended and cannot be filtered out. Gelatin and milk are colloids. If you shine a flashlight through gelatin or through water containing a few drops of milk, you can see the beam of light because it reflects from the particles. An emulsion is a type of colloid in which the two substances normally form a suspension. For example, oil and water form a suspension that eventually separates. If another substance is added that breaks the oil into colloid size particles, an emulsion forms. Examples of an emulsion are mayonnaise, butter, and margarine. The parts in a colloid can be solids, liquids, or gases, although there is no colloid of a gas in a gas. 1. Distinguish What distinguishes a suspension and a colloid? What distinguishes a colloid and a solution? 2. Observe You have two glasses of red liquid. One is red food coloring dissolved in water. The other is red gelatin dissolved in water. How can you tell which glass holds the gelatin? 3. Infer If you shine a flashlight through air in a darkened room, you can see that the air is filled with tiny particles of dust. What would determine whether this dust is a suspension or a colloid? 20 Matter and Atoms

15 Challenge LESSON 1 Pure Water Many people around the world have a shortage of freshwater, but live near oceans. Oceans contain pure water, many different dissolved salts, microscopic sea animals, and bits of wood, plants, and rock. Design a Procedure to Purify Seawater Design a procedure to separate the pure water in seawater from the other materials in it. Keep in mind that, in many poor countries, electricity is not as readily available as it is in the United States. Make your procedure as simple as possible so the average person could do it to obtain freshwater. Outline your design in the space below. Draw a diagram of the procedure and label each part clearly so that anyone could follow it to obtain freshwater. Matter and Atoms 21