Surface Area - Cart demo

Overview
Standards
Resources
Evaluations
Comments

Overview

Description:

This is a cart demo about how nanoparticles behave differently, in part because they have a high surface area:volume ratio. Visitors learn that smaller particles have a much higher proportion of their atoms on the surface. Visitors unfold paper cubes, drop alka-seltzer in water, turn potatoes black with iodine, and see fireballs to understand how surface area changes as you get small.

Objectives

Big Idea:

Nanoparticles have much more surface area than macro-particles, giving them different properties.

Learning goals:

Nanotechnology is very small.
Nanomaterials have different properties than other materials.
One reason for these different properties is an increase in surface area.

NISE Net Content Map:

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

Universal design:

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.

Checklist

Scientist reviewed? check_reviewed

Peer reviewed? check_reviewed

Visitor evaluation? check_reviewed

Nano Topics

Fundamentals

Audience

7 and up

Permissions

Creative Commons
Attribution Non-Commercial Share Alike

Standards

Physical science:

K-4: Properties of objects and materials

5-8: Properties and changes of properties in matter

9-12: Chemical reactions

9-12: Structure and properties of matter

Science and Technology:

K-4: Understanding about science and technology

5-8: Understanding about science and technology

9-12: Understanding about science and technology

Resources

Download all files (ZIP)

Video:

Evaluations

Exploring Materials - Surface Area

During the NISE Program Workshop at Fort Worth Museum of Science and History, school groups provided feedback on a variety of nano programs. The programs were performed January 16, 2007. Fifty-two visitors (students, teachers, and chaperones) completed self-administered surveys about the Surface Area program. Most respondents (96%) were 13 and 14 year olds. This formative evaluation shows that Read more

Comments

Possible alternative (or addition) to the Lycopodium Powder bit

Submitted by Luke Donforth on Wed, 04/07/2010 - 08:26.

This is a great collection of activities. From the write-up, it sounds like some folks might have difficulty with the lycopodium powder bit. There's a possible alternative to the lycopodium powder demonstration that uses isopropyl alcohol instead. This doesn't solve the problem of a venue where you can't have fire, but if you can have fire, you can do this instead or in addition to.

I used 91% isopropanol (works with 70%, but not as well), a small crucible, a long (6") lighter, and a "cloud in a bottle" set-up:
http://www.stevespanglerscience.com/experiment/00000030
(not the Exploratorium set-up: http://www.exploratorium.edu/snacks/fog_chamber/index.html, which is neat and has a good write up, but not what we need)

Pour a bit (~1 t) of the isopropanol in a crucible and set fire to it. It'll burn for a minute. This gives you a moment to talk about how the alcohol is flammable, but the reaction (burning) can only take place at the surface of the liquid where the oxygen and alcohol can interact. (I think it's easier to have a controlled bulk burn of isopropanol than lycopodium.)

When the fire extinguishes itself, add a teaspoon of isopropanol to the 2 L bottle and pressurize it with the pump (with rubber stopper adapter) from the cloud in the bottle set. When you pop the stopper out, you have a cloud of isoproponal droplets. Set the bottle down, and hold the lit lighter near the the mouth of the bottle. It might take a few seconds to catch (having the bottle on its side instead of upright can help) but when it does, the entire cloud burns very quickly. You'll get a whoosh, and the bottle may deform slightly from the heat.

I've got a video from prototyping, not a show presentation, but I'd be happy to share or talk about it if folks are interested.

I'm not sure what size the droplets in the cloud are. They scatter light and make a white cloud, so they're probably micron scale and not truly nano, but it does get to the surface area point.

Luke Donev
Educator - Museum of Nature and Science in Dallas
ldonev@natureandscience.org

This program is great! The

Submitted by Stephanie Long on Thu, 01/29/2009 - 17:03.

This program is great! The activities really drive home the teaching points. When I've seen this done visitors/students have really connected the dots and enjoyed the program. I'm in the process of adapting it from a cart activity to a large assembly program. I'll keep you posted on that.