8.2.1.1 Properties

Grade: 
8
Subject:
Science
Strand:
Physical Science
Substrand:
Matter
Standard 8.2.1.1

Pure substances can be identified by properties which are independent of the sample of the substance and the properties can be explained by a model of matter that is composed of small particles.

Benchmark: 8.2.1.1.1 Mixtures & Pure Substances

Distinguish between a mixture and a pure substance and use physical properties including color, solubility, density, melting point and boiling point to separate mixtures and identify pure substances.

Benchmark: 8.2.1.1.2 Metals vs. Nonmetals

Use physical properties to distinguish between metals and non-metals.

Overview

Standard in Lay Terms 

MN Standard in Lay Terms: All matter may be described as being one 'pure "thing or a mixture of two or more "pure" things. "Pure" here means that it is composed of one type of substance throughout or that it is thoroughly mixed. In the case of elements, it is one type of atom. In the case of molecules, it is a group of atoms that are chemically connected. In the case of solutions, it is a solute completely dissolved in a solvent. All of these substances have one thing in common; they are able to be described by a unique set of properties. It is also understood that these properties originate at the atomic level. For example, the element silver possesses a different set of properties than the element lead because of differences in atoms of silver and atoms of lead.

Big Ideas and Essential Understandings 

Big Idea:

A substance has characteristic properties, such as density, a boiling point, and solubility, all of which are independent of the amount of the sample. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties. National Academy Press (1996) National Science Education Standards

We can best understand chemical knowledge by observing and representing matter at multiple levels. These levels range from the unbelievably tiny subatomic level to the macroscopic level that we can see with our eyes. It is also important to recognize that the tiniest levels influence what occurs and is observed at higher levels

Matter, on all levels, has predictable properties that can be related to structures of the elements that make up that matter. These properties, resulting from the electronic and atomic structures, are responsible for behavior of elements, compounds, and mixtures on all levels. The periodic table is a useful tool for the organization of these properties on the elemental level.

Benchmark Cluster 

MN Standard Benchmarks

8.2.1.1.1 Distinguish between a mixture and a pure substance and use physical properties including color, solubility, density, melting point and boiling point to separate mixtures and identify pure substances

8.2.1.1.2 Use physical properties to distinguish between metals and non-metals.

THE ESSENTIALS:

"Scientific wealth tends to accumulate according to the law of compound interest. Every addition to knowledge of the properties of matter supplies [the physical scientist] with new instrumental means for discovering and interpreting phenomena of nature, which in their turn afford foundations of fresh generalisations, bringing gains of permanent value into the great storehouse of [natural] philosophy."["Lord Kelvin's Presidential address to British Association", 1871]

Correlations 
  • NSES Standards:

Content Standard B: Physical Science

PROPERTIES AND CHANGES OF PROPERTIES IN MATTER

A substance has characteristic properties, such as density, a boiling point, and solubility, all of which are independent of the amount of the sample. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

  • AAAS Atlas:

The Physical Setting: Atoms and Molecules

The Physical Setting: States of Matter

  • Benchmarks of Science Literacy:

4. The Physical Setting: D. The Structure of Matter

All matter is made up of atoms, which are far too small to see directly through a microscope. 4D/M1a

The atoms of any element are like other atoms of the same element, but are different from the atoms of other elements. 4D/M1b*

Atoms may link together in well-defined molecules, or may be packed together in crystal patterns. Different arrangements of atoms into groups compose all substances and determine the characteristic properties of substances. 4D/M1cd*

Equal volumes of different materials usually have different masses. 4D/M2*

Atoms and molecules are perpetually in motion. Increased temperature means greater average energy of motion, so most substances expand when heated. 4D/M3ab

In solids, the atoms or molecules are closely locked in position and can only vibrate. In liquids, they have higher energy, are more loosely connected, and can slide past one another; some molecules may get enough energy to escape into a gas. In gases, the atoms or molecules have still more energy and are free of one another except during occasional collisions. 4D/M3cd

Chemical elements are those substances that do not break down during normal laboratory reactions involving such treatments as heating, exposure to electric current, or reaction with acids. All substances from living and nonliving things can be broken down to a set of about 100 elements, but since most elements tend to combine with others, few elements are found in their pure form. 4D/M5*

There are groups of elements that have similar properties, including highly reactive metals, less-reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon). 4D/M6a

Carbon and hydrogen are common elements of living matter. 4D/M6c*

Most substances can exist as a solid, liquid, or gas depending on temperature. 4D/M8** (SFAA)

Materials vary in how they respond to electric currents, magnetic forces, and visible light or other electromagnetic waves. 4D/M9**

A substance has characteristic properties such as density, a boiling point, and solubility, all of which are independent of the amount of the substance and can be used to identify it. 4D/M10** (NSES)

Common Core Standards (i.e. connections with Math, Social Studies or Language Arts Standards):

English/Language Arts

Minnesota's newly revised (2010) English Language Arts (ELA) standards set K-12requirements not only for ELA but also for literacy in history/social studies, science and technical subjects.

6.13.3.3  Follow precisely a multistep procedure when carrying out experiments, designing solutions, taking measurements, or performing technical tasks.

6.13.4.4  Determine the meaning of symbols, equations, graphical representations, tabular representations, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.

6.13.7.7  Compare and integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, table, map).

6.13.8.8    Distinguish among claims, evidence, reasoning, facts, and reasoned judgment based on research findings, and speculation in a text.

6.13.9.9  Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic.

In conducting investigations on the properties of matter, students will need to be able to interpret and support their findings through the use of content-specific language and representations (graphs, tables, etc.) of the data that they have collected.  They will need to also use these tools to evaluate the data and information of others, including that found in related texts.

Minnesota K-12 Academic Standards in Mathematics (2007 version). Adopted September 22, 2008.

8.4.1.1 Collect, display and interpret data using scatterplots. Use the shape of the scatterplot to informally estimate a line of best fit and determine an equation for the line. Use appropriate titles, labels and units. Know how to use graphing technology to display scatterplots and corresponding lines of best fit.

8.4.1.2 Use a line of best fit to make statements about approximate rate of change and to make predictions about values not in the original data set.

8.4.1.3Assess the reasonableness of predictions using scatterplots by interpreting them in the original context.

These benchmarks apply to this standard as students could measure the mass and volume of different sized pieces of the same metal. They could then plot this data on a scatterplot and determine the line of best fit for their data. They could determine the slope and discuss the significance of their line.

Misconceptions

Student Misconceptions 

Todd, E. (1898). Discoveries of misconceptions regarding the properties of matter within the science of chemistry

A very interesting book regarding misconceptions and the properties of matter written by Emma Todd back in 1898 provides a wonderful insight into scientific thinking a century ago. It has been digitally archived and is able to be read online or downloaded onto an electronic reading device.

There many lists of misconceptions relating to naive ideas of matter, its composition and properties. The following list is a sample of what you will find from different misconception lists. A list containing many of these ideas compiled by the Operation Physics Elementary/middle school physics education outreach project of the American Institute of Physics. Author/editor is unknown.

1) Particles possess the same properties as the materials they compose.  For example, atoms of copper are "orange and shiny,"  gas molecules are "transparent," and solid molecules are "Hard."

2) Materials can only exhibit properties of one state of matter.

3) Relative particle spacing among solids, liquids, and gasses is incorrectly perceived and not generally related to the densities of the states.  (Microscopic model does not  represent macroscopic properties.)

4) Mass and volume, which both describes an "amount of matter," are the same property.

5) Particles misrepresented in sketches:  no differentiation is made between atoms and molecules.

6) Particles misrepresented and undifferentiated in concepts involving elements, compounds,mixtures, solutions, and substances.

7) Failure to perceive that individual substances and properties correspond to a certain type of particle.  Formation of a new substance with new properties is seen as simply happening rather than as a result of particle rearrangement.

Vignette

Students in Mr. D's science class had been discussing their ideas about matter.  Mr. D. wanted to move them toward looking at the various properties of matter, using some common substances.  "Each group is going to get 5 small paper cups to use .  The cups are labeled and contain one of the following powders: baking soda, baking powder, detergent, corn starch, and cream of tartar", he said as he added the list to the board.  "I would like you to start by closely observing each powder.  Renee will hand out the hand lenses, so that you can do that more efficiently.  Before you start your observations, I would like your group to come up with a chart in your science notebooks, so that you can organize your observations.  Use a piece of plastic wrap on your workspace, so that you can scoop small piles of powder onto it to help you observe more easily and not leave your table such a mess.  There are Popsicle sticks in each of the cups that you can use as a scoop.  You may want to use the Sharpie marker to label those with the substance name, so that we aren't transferring little bits of powder from cup to cup.  That will be important later.  You are also going to need to wear your goggles for this lab."

After students had time to observe, Mr.  D. made a large chart on the SMART Board and asked students to come up and write a few observations for each substance.  "So, how can we summarize the types of things that you observed? "We looked at color", Jayme offered.  "Even though they were all white powders they were a little bit different."  "All right, let's start a list of what you came up with", Mr. D. said as he began to record the list beside the chart on the SMART Board.  "Texture", Sarah said.  "Explain to me what you mean by texture", Mr. D probed.  "Well, like some of them were a fine powder and some were more like grains." 

After the student finished sharing their thoughts, Mr. D.  asked them, "What could we do to find out more about these powders?"  "We could mix them with something else and see what happens", said Blake.  "We have here some small dropper bottles of several liquids: water, vinegar, iodine and red cabbage juice.  See what you can find out as you add a small amount of each liquid to your powders.  What are some important things to consider here?"  "We should probably use a separate pile of powder for each one that we test and we should put the same amount of drops on each one", Taylor suggested.  "Both good ideas!  Let's see what we find out. Again, you are going to want to add this data to the chart that you already started."

When the students seemed to be done with their tasks, Mr. D. pulled their attention back to the front of the room.  "You can see I added some more columns to my table on the SMART Board, one for each liquid we tested.  How can you help me fill this in?"  Students hands went up as they offered observations such as, "dissolves in water", "turns purple with iodine", and "fizzes with vinegar".  "All of these things that we have been talking about", Mr. D. said as he gestured toward the chart, "are known as the properties of these substances - their color, how well they dissolve, and how they react with other kinds of matter.  These properties are predictable.  They are always the same for a certain type of substance no matter how big or small of a sample that we have.  We can use these properties to help us identify an unknown substance.  I am going to give you a 'mystery powder'.  Its properties will be the same as one of the powders that you have seen before.  See if you can identify it from the data that you have collected already on the properties of these powders.  Be ready to report back as a group in about 15 minutes.  I will expect you to have some evidence to back up your claim as to the identity of this substance!  While I am handing out the mystery powder, work with your group to write a definition for the word 'properties" as we have used it in class today.  We will check back on those as a wrap-up at the end of the period."

Resources

Instructional Notes 

Instructional suggestions/options; examples of best practices with a focus on active engagement practices (reflected in snapshot).

The core understanding in this standard is the idea that matter possesses properties that can be observed and measured. It is vital then that students understand what properties are. Using a formative assessment probe at the start might allow you to understand your student's depth of understanding in this area. The two probes listed in the assessments section would be particularly well suited for this. Much of the teaching for this standard may arise out of student observations and data gathered in lab activities. Characterizing substances is a fundamental part of what scientists do. Students will need encouragement to take their observations to deeper levels. That is one of the values of engaging students in activities like a mystery powder lab or the Water on Zork activity as they involve observing substances whose identity is unknown. Another idea here is to practice making observations of something familiar and then extending those skills to something unfamiliar. After characterizing common substances like clear liquids or white powders, allow students to make something more exotic and have them characterize this new substance using the properties they have worked with. This is also described in the assessments section and links for making simple polymers is provided in the additional resources section.

Selected activities, labs, lessons, problems, etc. Align w/Benchmark code. Should be reflected in snapshot.

Akron Global Polymer Academy (2011). Mystery Powders

Students will observe physical changes by adding water to eight different polymer            powders. They will record physical properties before and after adding the water.       Students will analyze their observations to identify the powders. They discover polymers are more than just plastic. 8.2.1.1.1

Explore Learning (2011). Mystery Powder Analysis Explore learning has a gizmo that explores mystery powders also. This is a subscription site, but a 30 day free trial membership is available. Students are able to perform multiple experiments using several common powders such as corn starch, baking powder, baking soda, salt, and gelatin. The results of the research on the known powders can then be used to analyze several unknowns using the scientific method. The unknowns can be a single powder or a combination of the known powders. 8.2.1.1.1

MNSTEP (2009). Mineral Density: Teaching Accuracy, Slope and Percent Error in the Earth Science Classroom This activity uses different sizes of mineral samples to collect mass and volume data so that students can generate a graph, plot a line of best fit, calculate slope and determine the precision and accuracy of their work. 8.2.1.1.1, 8.2.1.1.2

Yahoo Groups (2007) Metals, Nonmetals and Metalloids lesson ideas. This is a blog entry where a teacher is suggesting a lesson sequence in response to a question. Her ideas are arranged around the following essential question: How can you tell if an object is made out of a metal. 8.2.1.1.2

Water on Zork is an activity dealing with finding water on the fictitious planet of Zork.  Students evaluate a variety of liquids from the planet in order to determine which one is most likely water.  Students will form testable questions that will help them to identify the sample that is water, based on its known properties. Use the vocabulary list with caution, particularly the definitions given for scientific method and hypothesis.  8.2.1.1.1

Pittman R. (2004) Metals, Nonmetals and Metalloids? This lesson involves an inquiry into the properties possessed by metals and nonmetals. Students describe or measure a fairly standard set of properties to determine differences between these substances. 8.2.1.1.2

Instructional Resources 

Additional resources or links:

Additional content understanding about properties of matter can be found at the Inquiry in Action website maintained by the American Chemical Society. ACS (2011) Inquiry in Action

Waterways: A Minnesota Primer and Project Wet Companion is a Minnesota Department of Natural Resources publication that overviews the unique properties of water and how that allows it to function in Earth and biological systems.  Additional resources for the classroom are listed, as well as connections to the Project Wet curriculum.

Directions for making Slime and Gluep as well as background information about each of these polymers can be found at the Polymer Ambassador website.

This is an interesting way to engage students with vocabulary. The link provides an example of what you can do with matter vocabulary and definitions. Science-Class.net

New Vocabulary 

Vocabulary/Glossary: (align with standard, benchmarks, test specs)

  • Pure Substances: substances that have the same composition throughout. may be elements, molecules and solutions.
  • Elements: A substance that cannot be broken down into other substances by chemical or physical means.
  • Molecules: Particle containing two or more atoms that are chemically combined.
  • Solutions: A mixture in which one or more kinds of matter are mixed evenly in another kind of matter.
  • Mixtures: Two or more substances that are mixed together but not chemically combined
  • Particles: What matter is made up of. Can be atoms, molecules and compounds
  • Matter: something that has mass which can exist in the form of a solid, liquid, gas or plasma.
  • Property: A characteristic of matter that can be observed or measured.
  • Intensive Property: Property that does depend on the amount of matter present.
  • Color
  • Density: The measurement of how much mass of a substance is contained in a given volume
  • Melting Point: temperature at which a substance changes from a solid to a liquid.
  • Boiling Point: Temperature at which a liquid changes into a gas.
  • Solubility: A measure of how well a solute can be dissolved in a solvent at a given temperature
  • Malleability: The ability of a substance to be hammered into thin sheets.
  • Extensive Property: Property that does not depend on the amount of matter present.
  • Mass : Amount of matter present
  • Volume: A measure of how much space the matter of an object takes up.
Technology Connections 

Explore Learning: Gizmos Gizmos offers many computer simulations that are useful for students initially investigating a hard-to-visualize concept or in situations where an actual lab would be difficult to perform.  Many of the Gizmos allow students to manipulate variables to see how that affect the outcome of the investigation. There are three density gizmos that could be used to help students conceptualize this difficult concept. This is a subscription website, but free 30 day memberships are available. 8.2.1.1.1

The Dynamic Periodic Table is a wonderful interactive periodic table tool that allows students to examine groups of elements in multiple ways.Students may examine physical properties to examine similarities and differences between metals, nonmetals and metalloids. 8.2.1.1.1, 8.2.1.1.2

Founded in 1999, BrainPOP creates animated, curriculum-based content that engages students, supports educators, and bolsters achievement. Ideal for both group and one-on-one settings, BrainPOP is used in numerous ways, from introducing a new lesson or topic to illustrating complex subject matter to reviewing before a test. Content is aligned to academic standards and easily searchable with our online Standards Tool. Uniquely suited for 21st-century learning, all products are fully compatible with interactive whiteboards, learner response systems, projectors, Macs, and PCs. No downloading, installation, or special hardware is required. This is a subscription service that provides a free trial membership.

Cross Curricular Connections 

In studying elements, many times questions arise as to how that element was named. Elemental history provides opportunities to talk about world events that were happening at the time as well as variables that affected or directed the endeavors of the science community at that time. In studying properties of materials, discussions might arise concerning the role that these materials played in the development of societies at that time. For example, Alfred Nobel's discovery of nitroglycerin had profound effects on warfare in the mid to late 1800s or the development of Bakelite heralded the entrance of plastics into our world.

Assessment

Students:

Investigations with Polymers...Experimenting With Characterization. You have been charged by a leading toy manufacturer with characterizing two new polymers in order to determine which one would be most appealing to the 10-year-old market. They are looking to develop a suitable alternative to Silly Putty. Prepare two polymers according to the simple directions. Your task today and tomorrow is to compare and contrast as many properties of these substances as is appropriate for this room. Your finished product will be a lab report that details and documents your testings and your findings.

Keeley, P. (2005). Uncovering student ideas in science, volume 1. Arlington, VA: NSTA Press. 

Using the "Is it Matter" (p. 79) assessment probe at the start of a unit or discussion on matter, gives teachers a clear idea of what students perceive as matter.  It gives insight into whether students link physical and chemical properties to an explanation of whether a substance is considered matter. 

Keeley, P. (2007). Uncovering student ideas in science, volume 2. Arlington, VA: NSTA Press. 

Multiple formative assessments contained in this volume deal with properties of matter.  A few are: "Comparing Cubes" (p. 9 - mass, density, and melting point), "Turning the Dial" (p. 47 - boiling points, changes in state, and characteristic properties of matter) and "Boiling Time and Temperature" (p. 53 - boiling points, changes in state, and characteristic properties of matter) and "Freezing Ice" (p. 59 - characteristic properties and freezing point).  In addition to these being excellent ways to thresh out student ideas and misconceptions, these probes lend themselves well to short lab exercises to test those ideas.

Keeley, P. (2008). Uncovering student ideas in science, volume 3. Arlington, VA: NSTA Press.

Two formative assessment probes from this volume relate well to this standard.  "Is it a Solid (p. 25) assesses student understanding of what properties are characteristic of solids.  "Pennies" (p. 17) also looks at properties, but more so at the level of the atom.  This probe could also relate more specifically to benchmark 8.2.1.1.2, as classroom discussion begins on the properties of metals versus nonmetals.

Teachers:

What familiar substances can be best used to explore the concepts related to properties?

How can the concept of matter and its properties be threaded seamlessly throughout the eighth grade science curriculum?

What are the essential questions students need to answer to demonstrate an understanding of this standard?

Administrators:

You should see students engaged in hands-on lab activities that involve elements of inquiry. Students might be planning, communicating, observing, comparing and contrasting, questioning and hypothesizing. In other words, you should see students doing science. Technology use should be evident either in the way information is being presented or in the way students are communicating what they are learning. Displays of data gathered in lab could very well be visible. The enduring understandings and essential questions for this standard should be visible and able to be verbalized if an students was asked why they are doing what they are doing.

Differentiation

At Risk 

Snow, D. (2003). Noteworthy perspectives: Classroom strategies for helping at-risk students (rev. ed.). Aurora, CO: Mid-continent Research for Education and Learning.

In 2002, McREL conducted a synthesis of recent research on instructional strategies to  assist students who are low achieving or at risk of failure. From this synthesis of research, McREL identified six general classroom strategies that research indicates are particularly effective in helping struggling students achieve success:

Whole-class instruction that balances constructivist and behaviorist strategies

Cognitively oriented instruction which combines cognitive and meta-cognitive strategies with other learning activities

Small groups of either like-ability or mixed-ability students

Tutoring that emphasizes diagnostic and prescriptive interactions

Peer tutoring, including classroom-wide peer tutoring, peer-assisted learning strategies, and reciprocal peer tutoring

Computer-assisted instruction in which teachers have a significant role in facilitating activities

Complete results of this study  may be downloaded here.

English Language Learners 

Herr, N. (2007). The sourcebook for teaching science.

This page contains strategies to help teachers better attend to the needs of their ELL learners. These strategies are grouped according to the following learning tasks: listening, visualization, interpersonal communication, laboratory, demonstrations, reading and writing, instruction and vocabulary.

Klentschy, M. (2010). Using science notebooks in middle school. Arlington, VA: NSTA Press.

Strategies:

Front-loading: Teachers plan for words that ELL students will encounter as they do inquiry and within the particular content being studied.  They need to provide not only experience with vocabulary words (the "bricks"), but also the form and context in which they are used in spoken or written language ( the "mortar").

Word Wall: The teacher writes and discusses the needed vocabulary and posts the words on chart paper, sentence strips, or the board, making sure they remain in clear view for students to use as a resource when writing or speaking.

Kit Inventory:  Uses science materials from the current lesson, allowing students to question and discuss the scientific name of these items, their use, and description of the properties of those materials (made of plastic, cylinder-shaped, etc.) in their investigations.

Everyday Words and Science Words:  Purposely contrast the meaning of everyday words and science words (For example: "write down" versus "record").  These could be recorded on a chart for student reference.

Sentence Stems: Use abbreviated stems or scaffolds to help students begin writing in their science notebooks about their inquiry investigations:

  • I observed _____.
  • I wondered _____.
  • I thought _____ would happen.
  • Today I learned _____.
  • Questions I have now _____.

Charts: Teachers should model a variety of charts and how to use them for recording and reading information.  This helps students to have examples for eventually making their own charts, as well as to successfully use the vocabulary as it is presented in context.

Diagrams and Illustrations: Labeling diagrams, particularly those that the students drew themselves, reinforces the use of vocabulary and allows students to make relational connections to content.

Classification: Classification (which could include sorting, use of Venn Diagrams, T-charts, etc.) allows students to develop their understanding of the similarities and differences of (in this case) substances and to further interact with content specific words within the course context.

CLOZE:  This strategy involves providing students with a reading passage in which content specific vocabulary (the "brick" words) have been left out.   Words to include could be selected from a word wall or chart.

Concept Maps: Rather than merely learning recognition and definitions of science vocabulary, developing a concept map over the course of a unit helps students to tie those words into networks of related concepts.  Maps can be added to as the unit and the understanding develop, possibly adding new ideas or connections in a different color.

Extending the Learning 

G/T:

Teachers First is a educational support website that contains a list of strategies for working with gifted and talented students in your classroom. Many times it is not your "A" student that qualifies as Gifted and talented, but rather the student who is  not achieving and being disruptive.

Cogito is a website set up as an online community for gifted and talented students. There is a link to their chemical sciences page that provides information designed it to capture and highlight all the interesting conversations, articles, experts, and activities going on around the chemical sciences on Cogito.

Multi-Cultural 

Multicultural science education.  Official NSTA Position Statement.

Freelang.net hosts a English to Ojibwe and Ojibwe to English dictionary that may be used to look up meanings to vocabulary words.

Special Education 

Students With Disabilities is a position statement by the National Science Teachers Association concerning the inclusion of and basic adaptations for students with disabilities in the science classroom.

Many of the adaptations listed below for ELL students also work well for special education students.

Technologies for Special Needs Students: In their newsletter, "Tech Trek",  from the National Science Teachers Association, suggestions are given for using various technologies to make science more accessible to students.  Included are ideas for computer-assisted instruction, assistive technologies (such as voice-recognition software), as well as internet links and  additional resources.

Parents/Admin

Parents 

Try to encourage conversations between parents and their kids through the use of take home questions/inquiries. These could simply be the essential questions you are using to guide your lessons or they could be simple experiments that would provide the opening to the next day's lesson. Sometimes current events might provide the question or you might have an occasion to get information from their parents or grandparents childhood. Questions will help you to bridge the gap between school at home. Examples might include: Asking grandparents about weather proverbs they remember from their childhood or asking students to take a survey of family members regarding a local environmental issue or asking students to determine whether hot water or cold water freezes faster?

Comments

metals vs. non-metals

I am having trouble seeing how a mystery powder relates to standard 8.2.1.1.1 benchmarks. The activity connects to the standards but not the benchmarks upon which the state test is based. Students do not distinguish between mixtures or pure substances nor do they use density, melting or boiling points, etc. There is no mention of metals and non-metals or support for instruction.