Exploring Ice I MAIN MENU IN THE SOLAR SYSTEM C E SCIENCE & LITERATURE 2 L CONCEPT OVERVIEW 3 I S PRE K–GRADE 2 CONCEPTS 3 GRADE 3–GRADE 5 CONCEPTS 3 A LESSON SUMMARY & OBJECTIVES 4 M STANDARDS 5 E I ESSENTIAL QUESTION 6 N ACTIVITY QUESTION 6 E BACKGROUND 7 R ACT OUT THE SCIENCE 12 A MATERIALS 17 L S DEMONSTRATION 18 MAIN ACTIVITY 19 PREPARATION 19 TEACHING TIPS 19 WARM-UP AND PRE-ASSESSMENT 21 S PROCEDURES 22 DISCUSSION AND REFLECTION 25 CURRICULUM CONNECTIONS 25 ASSESSMENT CRITERIA 26 RESOURCES 27 O PHOTO GALLERY N D I R E This activity develops pre- C cursor understanding about the characteristics T of ice as a mineral, com- O pared to other minerals, R particularly in terms of Y hardness. Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL SCIENCE & LITERATURE “Those instruments which the Mineral- ogist takes to his assistance in the examination of the hardness are—the knife in half-hard and soft fossils, the steel in hard, and the file in perfectly hard fossils…HARD is a fossil that can- not be scraped with a knife, but rather gives fire with steel…VERY HARD, on which the file makes a weak impres- sion…and EXTREMELY HARD, on which the file makes no impression, but rather receives an impression We often think of scientific data as from the fossil…HALF-HARD is a quantitative, that is, precisely expressed solid fossil which does not strike fire through the use of mathematics. Yet precision can also be attained through the with steel, but may in some measure use of language to describe qualities of be scraped with a knife…Those solid phenomena, producing qualitative data. The fossils are SOFT which may be easily leading geologist of his times, Werner used straightforward descriptive words to pro- scraped with a knife, but suffer no pose a relative hardness scale. Through his PRINT impression from the nail…VERY SOFT carefully defined meanings, he was able to are all solid fossils which may not only present a whole system of how to identify and classify “fossils,” in those days referring be easily scraped with a knife, but also to rocks, minerals, and ores (rocks that receive an impression from the nail.” contain metals). — Abraham Gottlob Werner (1805). Excerpt from an original imprint of the English translation Treatise on the External Characters of Fossils 2 Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL CONCEPT OVERVIEW This activity develops precursor under- GRADE 3–5 CONCEPTS standing about the characteristics of ice I Geologists define a mineral as a naturally as a mineral, compared to other minerals, occurring solid with a crystalline structure. particularly in terms of hardness. I “Crystalline structure” is a regular geometric Concepts: arrangement of atoms and molecules that I Solids compose the mineral. I Crystal I A rock is a mixture of different minerals I Minerals I Water ice is a naturally occurring solid with a crystalline structure. I Hardness I Ice is a mineral. I Scales I This activity provides a concrete The hardness of ice can be measured by experience of: comparing it with other objects (a relative hardness scale) or by comparing it to a set I Evidence of ice as a mineral of criteria (an absolute hardness scale). I Comparing the relative hardness I of ice to other objects Different scales of measurement are used to compare different properties I Creating a relative hardness scale of phenomena. PRE K–GRADE 2 CONCEPTS I A mineral is a special kind of solid with a crystalline structure. I A crystalline structure is a regular shape PRINT formed by the arrangement of the building blocks (atoms and molecules) of the mineral. I Ice is a solid with a crystalline structure. I Ice is a mineral. I Ice is harder than some things and softer than others. I A scale of measurement is used to compare properties of phenomena. 3 Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL LESSON SUMMARY & OBJECTIVES Geologists teach that a mineral is a naturally Objective 1: Notice that ice forms occurring solid with a crystalline structure. as crystals This activity explores how ice compares to Although the individual molecules are too small other minerals, and how thinking about ice as for us to see, we can view crystal matrices a mineral may help us as we explore for the of ice and we can understand that when ice presence of ice in the Solar System. Specifi- freezes, its forms a crystalline structure. cally, this activity looks at the property of Objective 2: Notice that ice fits the hardness, an object’s resistance to scratching, definition of a mineral which depends on the molecular bonds. We Geologists define a mineral as a naturally can quantify our understanding of hardness occurring solid with a crystalline structure. by making a relative hardness scale. Ice fits this definition and can be compared with other minerals. Objective 3: Notice that ice is harder than some things and softer than others Geologists categorize minerals according to their physical characteristics. Hardness is one characteristic that students can experience directly. PRINT 4 Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL STANDARDS PROJECT 2061 BENCHMARKS Content Standard A Science as Inquiry: 4D—The Physical Setting Structure Abilities necessary to do scientific inquiry of Matter GRADES K–4, PAGE 122 GRADES K–2, PAGE 76 Communicate investigations and explana- Objects can be described in terms of the tions. Students should begin developing material they are made of (clay, cloth, paper, the abilities to communicate, critique, and etc.) and their physical properties (color, size, analyze their work and the work of other shape, weight, texture, flexibility, etc.). students. The communication might be spoken or drawn as well as written. 1C The Nature of Science: The Scientific Enterprise Content Standard E Science and GRADES K–2, PAGE 15 Technology: Understanding about In doing science, it is often helpful to work science and technology with a team to share findings with others. GRADES K–4, PAGE 138 All team members should reach their own Scientists and engineers work in teams with individual conclusions, however, about what different individuals doing different things that the findings mean. contribute to the results. This understand- ing focuses primarily on teams working NSES together, and secondarily, on the combination Content Standard B Physical Science: of scientist and engineer teams. Properties of objects and materials GRADES K–4, PAGE 127 Objects have many observable properties, including size, weight, shape, color, temper- ature, and the ability to react with the other PRINT substances. These properties can be meas- ured using tools such as rulers, balances, and thermometers. 5 Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL ESSENTIAL QUESTION ACTIVITY QUESTION How can we understand ice as a mineral? How hard is hard? How is ice considered a mineral? What features What observations can we make about the does ice share with other minerals? What is a hardness of ice as one of the qualities that crystalline structure? define it as a mineral? What can we say, draw, write about the hardness of ice that we look at, touch, and examine in class? PRINT 6 Exploring Ice LESSON 3 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IS A MINERAL BACKGROUND What is Hardness? Ice meets the criteria of the definition for Hardness is a property of a mineral that a mineral: depends on the strength of its molecular I Solid (for ice: below 0º Celsius, bonds. Hardness is one measure of the 32º Fahrenheit) strength of the structure of the mineral relative I Homogenous (all parts of it are the same) to the strength of its chemical bonds. The I hardness of a mineral is often measured by Naturally occurring, (on Earth where it is what it takes to make a scratch mark on it. below freezing) Minerals with small atoms, packed tightly I Has a crystalline structure together with strong covalent bonds through- I Has a definite chemical composition (H2O) out tend to be the hardest minerals. The I softest minerals have metallic bonds or even Formed by inorganic processes weaker van der Waals bonds as important (Hurlburt, C. and Klein, C., Manual of Mineralogy. NY: John Wiley and Sons, Inc.) components of their structure. Hardness is not the same as brittleness, which is a measure Ice is a mineral with the chemical formula of how easily something breaks and is related H2O. However, it must be in a frozen state to to the crystalline structure of the mineral. qualify as a mineral. The solid phase of water normally occurs at or below 32 ºF, 0 ºC, or How is ice a mineral? 273ºK. Ice belongs to the hexagonal crystal Geologists view ice, especially large-scale system. Ice has a Mohs hardness of 1.5. glacial ice, as a mineral. Ice shares many features with other minerals, but it is also Whose idea is it, anyway? different in some important ways. Most In the history of science, we learn that solids are denser than their own liquid scientific ideas are credited to individuals form. Water is very different. Its solid who first publicize their insights within the PRINT form (ice) is less dense than its liquid form science community. Often, many people are (water), and therefore ice floats in water. working on the same ideas and it is difficult This characteristic keeps bodies of water, to tell whose idea a discovery really is.