Powers of TenFrom Meters to Nanometers and Beyond

Rob Snyder and Mort SternheimJuly 2012

Going Up the Powers of Ten Scale

Given the following information, many students comprehend both the distance and the speed.

Distance from the sun to Earth = 1.5 x 1011 metersSpeed of light in space = 3.0 x 108 meters per second

Moreover, many students can manipulate the data to answer a question like: How long does it take for sunlight to reach Earth?

They seem to be comfortable with objects that are seen, distances they have traveled, commonly photographed objects or images as well as the scale of maps and globes.

Going down the Powers of Ten Scale is much more of a challenge

• Mathematical operations that describe very small dimensions involve scientific notation with negative powers of ten.

• They are less familiar with instruments make indirect measurements of very small dimensions than with instruments such as a telescope.

• Structures with very small dimensions involve specific interactions between and arrangements of atoms, ions and molecules.

A Powers of Ten Data Table can be used to enter 14 progressively smaller measurements or calculations

The measurement Meters Centimeters Nanometers

X 100 X 102 X 109

X 100

The first challenge is to determine how many rows of data can be filled using the available measurement instruments.

The second challenge is to provide entries for remaining row and record data in the nanoscale and subnanoscale rows.

Common items and measurement tools can be used to initiate a process of going down a Powers of Ten scale.

Magnifiers help obtain the last significant digit in a measurement.

A USB microscope can measure openings in coffee filters and sizes of coffee grounds so that measurements can be

recorded on the data table.

Students can learn how to calibrate a measurement instrument that utilizes imaging technology.

Spectrometers can be used to add more data.

Wavelengths of visible light approach the nanoscale realm.

The activity document also includes descriptions of categories of filters with openings smaller than

wavelengths of light.

http://www.sciencedaily.com/releases/2008/02/080222095403.htm

A study of atoms and ions (and subatomic particles) extends the Power of Ten scale beyond the nanoscale.

Source:http://www.chem1.com/acad/webtext/atoms/atpt-6.html#SIZE

A picometer (pm) = 1 x 10-12 meters

152 picometers = 152 x 1012 meters = 1.52 x 1010 meters

An activity adapted from Nanosense is available at several stations to explore

Powers of Ten.

• The activity – http://nanosense.org/activities/sizematters/sizeandsca

le/SM_Lesson2Teacher.pdf• On STEM Ed web sites

– www.umassk12.net/nano/Saturday• Other useful nanoscience materials

– http://nanosense.org/index.html

How do we generate images of structures with nanoscale dimensions?

Tomorrow, you will build a model that simulates measurements made with a device called an Atomic

Force Microscope..

A Few Questions

• What can be added to the sequence of activities to more effectively develop a nanoscale perspective?

• What skills and perspectives developed during this activity support the study of other STEM topics?