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Silver Nanoparticles

Nanosilver: Miracle or menace?A science curriculum unit for 7th and 8th grade students

Created by: Lori Andersen, Amy Morgan Schmidt, & Carol Tieso

| Purpose | Target Audience | Appropriateness for Gifted Learners | Prerequisites for Students | Major Instructional and Grouping Strategies | Assessment | Learning Activities | Resources | Student Products | Nature of Differentiation | Opportunities for Talent Development | Alignment of Curricular Components | Ease of Use Rationale

Purpose

This unit engages students in a study of the concept of scale, and the nanoscale in particular, to support student learning about nanotechnology in a problem-based learning context. Students will explore size-dependent effects and learn about technologies that use unique properties that occur at the nanoscale. Nanotechnology is a controversial, socioscientific issue that presents both potential benefits and risks to society. Students will explore the implications of the use of a particular type of nanotechnology - antimicrobial materials that contain nanoparticle silver

The concept of scale is the least researched of all of the cross-cutting concepts in the K-12 Framework for Science Education (2011). Recent research (Tretter, Jones, Andre, Negishi, & Minogue, 2006) suggests that a sense of the size of small objects does not develop until late in high school because students lack experiences with microscopic objects. Students have difficulty comparing the sizes of objects that are smaller than themselves. This difficulty exists because people have very few mental size landmarks due to a lack of experiences with objects on the micro-, nano-, and atomic scales. This unit aims to provide students with experiences that will help them to develop unitizing strategies, mental size landmarks, and cognitive schema regarding the relative sizes of small objects. This ability is necessary to understand nanoscience and the implications of nanotechnology.

This unit about nanoscience teaches students to become educated consumers of nanoscale technology.

Target Audience

High ability learners in seventh and eighth grade.

Appropriateness for Gifted Learners

The material in this unit extends the middle school science curriculum beyond the requirements of the Next Generation Science Standards (NGSS; Achieve, 2013). The 2013 NGSS does not includes specific information about nanotechnology.

Specific reference to nanotechnology is found in the Virginia Standards of Learning. "Nanotechnology is the study of materials at the molecular (atomic) scale. Items at this scale are so small they are no longer visible with the naked eye. Nanotechnology has shown that the behavior and properties of some substances at the nanoscale (a nanometer is one-billionth of a meter) contradict how they behave and what their properties are at the visible scale. New discoveries based on nanoscience investigations have allowed the production of superior new materials with improved properties (e.g., computers, cell phones). Recognize examples of the use of nanotechnology and its applications." (VADOE, 2010)

This unit extends content beyond the NGSS performance expectations in Physical Science beyond the identification of materials by their properties (e.g. 5-PS1-3 http://www.nextgenscience.org/5ps1-matter-interactions and MS-PS1-2 http://nextgenscience.org/msps1-matter-interactions ). Students explore the scientific models that explain behavior at the nanoscale and compare these models to the models that explain behavior at the visible scale.

The use of nanosilver as an antimicrobial agent is the specific application that is explored in this problem-based learning unit. Other applications of nanotechnology are explored through the lessons on the unique properties of the nanoscale, applications of the nanoscale, and in a learning center where students can explore applications in areas of interest, such as medicine.

Advanced mathematics content can be incorporated into this unit. Math concepts such as working with integer powers of ten (CCSS.MATH.CONTENT.8.EE.A.3), performing operations with numbers expressed in scientific notation (CCSS.MATH.CONTENT.8.EE.A.4) , determining surface area to volume ratio (CCSS.MATH.CONTENT.7.G.B.6), and modeling using linear, quadratic, or exponential functions (MATH.CONTENT.HSF.LE.A.1) are used in this unit to reinforce student understanding of size, scale, and to provide evidence-based arguments for unique properties observed at the nanoscale.

Prerequisites for Students

Students should have some experience with metric prefixes and scientific notation. Some prior knowledge of physical and chemical properties of matter is assumed (e.g. this builds on the knowledge of the properties of matter indicated by NGSS performance expectation 5-PS1-3). Students should know that matter has some physical and chemical properties that are characteristic of that substance and do not depend on the amount of that substance, such as color, density, boiling point, melting point, etc.

Students are expected to be at the novice level of scale concept development. At the novice level, students have developed some number sense, are able to use measurement tools (eg. rulers, tape measures), can conceptualize relative size, and are developing skills in measurement estimation (Jones & Taylor, 2009). This unit will transition students into the developing level of scale concept development. At the developing level, students: develop proportional reasoning skills, understand different types of scales, visualize scales, use body rulers for measurement and estimation, are aware of changing scales, understand surface area to volume relationships, and convert measurements and scales (Jones & Taylor, 2009).

Major Instructional and Grouping Strategies

Major instructional strategies used in this unit include:
  • Taba Model of Concept Development (Concept-based teaching)
  • Brainstorming
  • Higher-level questioning
  • Inductive Teaching
  • Inquiry-based Teaching
  • Constructivist Learning
  • Affective Learning and Character Education (traits of successful scientists)
  • Attribute Listing (for creative idea generation)
  • Paul's Model of Reasoning

Flexible grouping is used in this unit. Flexible grouping is when there is whole group instruction at the beginning of the lesson, and then students are regrouped based on another criteria, such as readiness, interest, or skill level. Research shows that this type of grouping can have significant effects on students achievement (Tieso, 2003). For inquiry investigations, students work in small groups of 3-4 students. For some activities in this unit, students are grouped by interest, readiness, or skill level.

Assessment

Students are assessed using a variety of methods. Preassessment prior to starting the unit allows the teacher to gauge student readiness and current levels of knowledge. Students who demonstrate advanced knowledge should be given alternate activities which are suggested in the resource section. Ongoing informal assessment occurs throughout the unit; specific assessment "look-fors" are specified in each lesson plan. The products that the students produce in the different activities provide opportunities to monitor student growth, provide student feedback, allow for student self-reflection, and to differentiate content or instruction.

Learning Activities

The learning activities in this unit use constructivist learning, analytical thinking, problem-solving, research, creativity, and investigation. In Lesson 3, students analyze the individual traits that are needed for success in careers in science and other fields. In Lesson 4, Scales and Sizes of Objects, the class constructs a scale continuum using the information that individual students have found during their investigations of the sizes of objects. In Lesson 5, the class inductively deduces the unique properties of the nanoscale using their observations during a set of inquiry activities. In Lesson 6, the class constructs an attribute list for nanotechnology products and analyzes the properties of the nanoscale that make these attributes possible. The culminating activity of Lesson 6 allows students to use attribute listing to generate new nanoproducts or improve existing products using nanoscale properties. In Lesson 7, students use Paul's Reasoning Model and the William and Mary Research Model to analyze the use of antimicrobial clothing from the perspectives of stakeholders. Students develop recommendations based on their analyses of primary source information and create a presentation.

Resources

This unit uses a variety of authentic resources which are listed on the resources page. These materials are closely aligned with the content knowledge goals of this unit. The materials are highly motivating for students because relevant, real-world information is provided at an appropriate level of challenge.

Student Products

  1. Generalizations for scale concept via Taba Model of Concept Development
  2. Profile of a career of interest that includes required traits and why the traits are needed
  3. Scale continuum; table of student-selected objects that includes size and scale information
  4. Data and analyses from inquiry activities
  5. Generalizations from inductive reasoning about inquiry activities
  6. Attribute list for nanotechnology products
  7. Advertisement for student-invented new product that uses nanotechnology
  8. Stakeholder analysis for problem
  9. Presentation for school board

Nature of Differentiation

This unit uses preassessment to identify student differences. In Lesson 3, the career investigation is differentiated by interest. In Lessons 3, 6, and 7, the career profile, nanotechnology product advertisement, and presentation are differentiated by communication preference. The entire unit is designed using content that is at a higher level of abstraction, higher level of complexity, and increased depth compared to the standards middle school science curriculum. The pacing is faster than typical middle school curricula. The content is authentic because a cutting-edge, contemporary science topic is explored in a context that relates to middle schools students - the use of nanotechnology in school physical education clothing. Appropriate scaffolding is provided to assist all learners in mastering the goals of this unit. The nature of the content, the highlighted practicing professional chosen for discussion of traits, and the profile of a college preparatory program support talent development in STEM. However, allowing students to choose a career to investigate that matches an area of personal passion differentiates this talent development activity by interest.

Opportunities for Talent Development

The unit includes the following opportunities for talent development:
  • Students can engage in activities aligned with their individual strengths, preferences, or interests (Lesson 3)
  • Students make connections between unit activities and potential career fields (Lesson 2, Lesson 3, Lesson 7, Interest/Learning Center), leadership opportunities (Lesson 7), or real-world applications (Lesson 2, Lesson 5, Lesson 6, Lesson 7, Interest/Learning Center)
  • Teachers can spot potential talent (Preassessment, Lesson 1, Lesson 3, Lesson 5, Lesson 6, Lesson 7)
  • Students can interact with role models or professionals in the field (Lesson 2, Lesson 3, Lesson 6, Lesson 7, Interest/Learning Center)
  • Students explore advanced content (Entire Unit)
  • Students acquire the skills, methodologies, and dispositions of the practicing professional (Lesson 3, Lesson 4, Lesson 5, Lesson 6, Lesson 7)
  • Students investigate real-world problems (Lesson 7) and develop authentic products (Lesson 6, 7).
  • Students reflect about individual strengths, goals, values, accomplishments, interests, and plans (Lesson 2, Lesson 3)

Alignment of Curricular Components

The unit contains seven lessons. The unit contains eight of the talent development opportunities as described in the previous section. The unit has been designed such tha the components flow in a logical sequence and are closely aligned.

Ease of Use

  • The curriculum components include: lesson plans, embedded video clips, links to supporting websites, supplementary reading materials for students and the teacher, and masters of all handouts referred to in the lesson plans.
  • Each lesson has detailed descriptions to aid teacher implementation including notes to alert the teacher to prerequisite knowledge that may need to be reviewed and the rationale/purpose for each activity.
  • The unit has been field-tested and revisions have been made.

Website by Lori Andersen, 2012