Why are Seashells so Strong?

Overview

Lizzie Hager-Barnard [4]

Description:

In this hands-on activity, visitors explore the structure of seashells and learn that seashells are a composite material made of both inorganic and organic materials. Visitors compare the mechanical properties of plaster bricks and dried sheets of glue, which helps them discover that both toughness and hardness are important mechanical properties. To see what a shell would be like if it were not so tough, visitors try to break normal shells and shells that have been either baked or soaked in bleach.

Objectives

Big Idea:

Shells have great mechanical properties, including high hardness and high toughness. Shells’ great mechanical properties are due to both their nanoscale structure and their combination of inorganic and organic materials.

Learning goals:

That an object’s materials and structure determine its strength
That a composite material is a mixture of two or more materials
The difference between toughness and hardness
The differences in mechanical properties between dried glue sheets and plaster bricks
That bleach can remove organic material and baking can harm/degrade organic material

NISE Net Content Map:

Nanometer-sized things are very small, and often behave differently than larger things do.

Scientists and engineers have formed the interdisciplinary field of nanotechnology by investigating properties and manipulating matter at the nanoscale.

Universal design:

Repeat and reinforce main ideas and concepts.

Provide multiple entry points and multiple ways of engagement

Provide physical and sensory access to all aspects of the program. Visitors can touch, see and hear different elements of the program.

Credits

Developed for the NISE Network with funding from the National Science Foundation under Award Numbers 0532536 and 0940143. Any opinions, findings, and conclusions or recommendations expressed in this product are those of the authors and do not necessarily reflect the views of the Foundation.

Owning institution:

Lawrence Hall of Science [6]

Checklist

Scientist reviewed? check_reviewed

Peer reviewed? check_reviewed

Visitor evaluation? check_reviewed

Adaptable Formats

Cart demonstration [2]
Classroom activity [7]

Nano Topics

Audience

All ages [11]

Permissions

[19]
Creative Commons
Attribution Non-Commercial Share Alike

Catalog section:

Programs

What kind of program?:

Cart demonstration

Adaptable formats:

Cart demonstration

Classroom activity

Nano topics:

Art and nature

Bio and medicine

Materials, tools, and applications

Audience:

All ages

Content keywords:

seashells

nacre

hardness

toughness

strength

composite material

mechanical properties

Highlight this product during NanoDays?:

This is a NanoDays product.

K-12:

This product would be useful for K-12 teachers.

Standards

Physical science:

K-4: Properties of objects and materials

5-8: Properties and changes of properties in matter

9-12: Structure and properties of matter

Life science:

K-4: Characteristics of organisms

5-8: Structure and function in living systems

9-12: Matter, energy, and organization in living systems

Science as inquiry:

K-4: Abilities necessary to do scientific inquiry

5-8: Abilities necessary to do scientific inquiry

9-12: Abilities necessary to do scientific inquiry

Resources

[3]

Download all files (ZIP) [3]

Files:

Lesson plan [20]

Evaluations

Comments

Why are Seashells so Strong?

Why are Seashells so Strong?

Description:

Big Idea:

Learning goals:

NISE Net Content Map:

Universal design:

Owning institution:

Checklist

Adaptable Formats

Nano Topics

Audience

Tags

Permissions

Catalog section:

What kind of program?:

Adaptable formats:

Nano topics:

Audience:

Content keywords:

Highlight this product during NanoDays?:

K-12:

Physical science:

Life science:

Science as inquiry:

Download all files (ZIP) [3]

Files: