real science-4-kids...telescope, much of what we have discovered about the universe would still be...

Real Science-4-Kids

Rebecca W. Keller, Ph.D.

Chem istr y Co nnects to Technology

Workbook Level I A

Cover design: David KellerOpening page: David KellerIllustrations: Janet Moneymaker, Rebecca Keller (unless otherwise noted)Support Writer: Dave MulderEditing: Angie SauberanPage layout: Kimberly Keller

Copyright © 2008 Gravitas Publications, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. No part of this book may be used or reproduced in any manner whatsoever without written permission.

Real Science-4-Kids/ Kogs-4-Kids™: Chemistry Connects to Technology: Level I A

ISBN: 9780979945984

Published by Gravitas Publications, Inc.P.O. Box 4790Albuquerque, NM87196-4790www.gravitaspublications.com

Printed in the United States of America

Special thanks to G.E. McEwan for valuable input.

Introduction Technology

I.1 What is technology?

I.2 Archimedes: a great inventor

I.3 How science shapes technology

I.4 How technology shapes science

I.5 Discussion questions

I

2 Chemistry connects to . . . . . .

I.1 What is technology?Think for a moment about what it might be like to live in the 14th century. Imagine that you can travel back in time and that you find yourself in a small European village in 1392.

What do you think you would find? How would you cook your food? Would you use an oven, a fire, or a microwave? How would you eat your food? Do you think you could use a plastic cup to drink your milk? How would you go from one city to the next? Could you get on a train, or would you have to walk, or would you ride a horse? How could you send a message to your mom to tell her that you’ll be late for dinner? Could you e-mail her, or could you call her on your cell phone?

Technology Level I Introduction 3

How would you get clothes? Could you shop at a 14th century mall or on the internet? And what would your clothes be made of? Do you think you could find pink spandex shorts, or would they have to be made of brown cotton? Think for a moment about how different everything would be if you were to live in the 14th century.

Many of the items that you use today are a result of technology. Your cell phone, microwave oven, washing machine, and plastic cup are all the result of a combination of scientific discoveries and engineering. This combination of scientific discoveries and engineering has allowed people to invent products that have improved the way people live. Technological advances have improved our health, the food we eat, the clothes we wear, how we travel, and how we communicate with one another. There are a few drawbacks to some aspects of technology (such as pollution), but overall, technology has greatly improved many aspects of living for most people.

The word “technology” comes from the Greek words techne, which means “craft,” and logy, which means “scientific study of.” So technology means the “scientific study of craft.” Craft, in this case, means any method or invention that allows humans to control or adapt to their environment.

I.2 Archimedes: a great inventorHow did technology get started? Inventions and tool making have been around for as long as human beings have walked the earth. But modern technology began once scientific thought (philosophy), astronomy, and mathematics began to blend together; this occurred sometime after the 15th century.


The first inventor who combined engineering with science was Archimedes of Syracuse (287 B.C.-212 B.C.). He is credited with inventing the Archimedean screw, which is used for raising water. The Archimedean screw is still used in Egypt today. He is also credited with inventing the cross-staff, which is used in astronomy. And he invented the odometer, which measures how far someone has traveled.

The most famous story about Archimedes is the one in which he was told by the king to find out whether the king’s crown was made of solid gold. He had to figure out a way to test the crown in order to see whether it was made of gold, and he had to do so without melting it. This was a puzzle for Archimedes. It is said that one day he noticed that his body would displace the bath water. Seeing this, he realized that he could use the displacement of water as a way to measure the crown’s volume (and thus its density upon weighing it). As the story


goes, it was at this point that Archimedes jumped out of the tub and ran through the streets naked; as he ran, he shouted, “Eureka! I have found it!” No one is certain whether the story is true, but it does give you an idea of how exciting new discoveries in technology can be!

I.3 How science shapes technologyBefore formal scientific disciplines (such as chemistry, physics, astronomy, and biology) were defined, many early inventors simply experimented with items around them and tried to come up with ways to improve their lives. Inventions and discoveries often happened by accident. Glass, for example, is said to have been discovered by Phoenician sailors in 4000 B.C. According to the ancient story, the sailors were cooking on nitrate blocks. The blocks were melted by the fire, and they mixed with the sand below. This created a crude glass. No one could have guessed at the time, but these sailors helped pave the way for Galileo and others to use telescopes for observing the stars.

The earliest star gazers had no way to see beyond what they could observe in the sky with their own eyes. For these early astronomers, the technology for seeing beyond our solar system and galaxy did not yet exist. In the early 1600s, Galileo Galilei observed the heavens through the first telescope. It took both the scientific idea that glass could magnify far away objects and the craft of glass making in order for the first telescope to be invented. Improvements in how much a telescope could magnify were accelerated by Sir Isaac Newton’s ideas regarding using a curved mirror rather than glass for the


lens. Because Newton understood the science of light, called optics, he was able to add to the technological advance of the telescope. Science shapes technology, and without an understanding of basic scientific principles and without the gathering of new scientific facts, technological advances in any area would be impossible.

I.4 How technology shapes scienceLooking at it from the other end, how does technology shape science? Going back to Galileo and Newton, how do you think the telescope has changed our understanding of not only our own solar system, but of the whole universe?

The telescope ushered in a new and fascinating scientific discipline that we now call astronomy. Astronomy is the scientific study of the planets, stars, and other objects in the universe. Before the telescope, no one had ever observed a nebula, for example, and no one knew how many planets were in our solar system. Without the technology of the telescope, much of what we have discovered about the universe would still be unknown.

The telescope also opened up many ideas and changed the way people thought about cosmology. Cosmology is the study of the universe. It would be very difficult to study the universe if we had no way to look beyond our own planet. The technology of the telescope brought modern cosmology into the arena of serious scientific study. The telescope enabled scientists to measure, predict, and quantify many features of the universe. By applying mathematics to careful


observations generated by the use of telescopes, scientists changed the way people thought about the universe and themselves.

I.5 Discussion questions1. Think about a piece of technology that you use today, such as a

cell phone or a television. List all of the materials that the item is composed of. For example, does the item contain plastic, metal (what kind?), glass, etc.?


2. Now think about one of those materials, and try to answer the following questions. Use library or internet resources to research the answers.

a) How is it made?

b) Where is it made?

c) Who designed it?


3. Think about the process for designing and making the material.

a) Which scientific disciplines are involved in this process?

b) Explain how chemistry or physics helped in creating the piece of technology you described.

1.1 “Seeing” atoms

1.2 Scanning tunneling microscope

1.3 Atomic force microscope

1.4 Nanotechnology

1.5 Activity

1Small-Scale Science Technology

Technology Level I Chapter 1 11

1.1 “Seeing” atomsHow small are atoms? Atoms are too small to even picture! The cells that make up living things are small, but even the smallest living cell is made up of billions of atoms! If atoms are so small, how can we be sure they exist?

For a long time, the answer to that question was, Well, we have lots of experimental evidence that makes it seem like atoms exist, but we can’t really see atoms because they are just too small! However, in the 1980s a new microscope technology was invented. This new device was called a scanning tunneling microscope, or STM. An STM makes it possible to “see” atoms.


1.2 Scanning tunneling microscopeA scanning tunneling microscope is not a typical microscope. It does not work with light or lenses, and you don’t look through it. In fact, when using an STM, you do not actually “see” the atoms, at least, not in the way that you are looking at this page in front of you.

An STM works by “scanning” the surface of an object and then projecting an image of the surface on a computer monitor or other screen. The STM has a metal probe called a stylus that actually does the scanning. The stylus is extremely sharp; it comes to a point that is only one atom wide! This stylus moves very close to the surface of the object being scanned. The gap between the tip of the stylus and the object is about as wide as one atom, or it may be even smaller.


The STM works by passing the stylus back and forth over the surface of the object that is being scanned. The moving stylus is controlled by a computer. Human beings are not precise enough to keep the stylus at the right distance from the scanning surface. As the stylus moves, it “picks up” electrons from the surface of the object. The electrons show where the atoms in the object are located. The signals created by these electrons are strengthened and then projected onto a monitor to create an image.

An STM can produce phenomenal images of a surface, but it has another amazing function. An STM can be used to “grab” individual atoms! The computer controlling the STM can then move the atoms to specific locations. In 1990, researchers at IBM used an STM to grab individual xenon atoms. It took over 20 hours, but they were able to arrange 35 atoms into the letters I, B, and M to make the smallest company logo ever.


Since then, researchers have been working on ways to move atoms around more quickly. They are discovering ways to make incredibly tiny structures, one atom at a time.

1.3 Atomic force microscopeOne of the drawbacks of the early scanning tunneling microscopes was that they could only be used to scan objects that conduct electricity easily, like metals. Therefore, they could not be used to create images of substances that were not conductors of electricity, such as plastics or living tissues. In the years since STMs were invented, several other types of probe microscopes have been developed. They work in slightly different ways, but the basic principle remains similar; the microscopes allow scientists to get an extremely close-up image of an object. One type is called an Atomic Force Microscope, or AFM. An AFM can scan many different types of surfaces, including metals and nonmetals.Like an STM, an AFM has a very short tip. But instead of picking up electrons like an STM, an AFM can “see” atoms by just bumping into them (that is, by measuring the force between an atom and the tip). Because everything is made of atoms, an AFM can see all kinds of things, not just conductors.

1.4 NanotechnologyThe science of designing and working with extremely small things is called nanotechnology. The nano in nanotechnology means “nanometer,”


and so nanotechnology means “building things that are nanometers in size.” A nanometer is one billionth of a meter; that is, it takes one billion nanometers to equal one meter. Remember that scientists use the metric system to measure things. A meter is the standard metric unit for length. One thousandth of a meter is called a millimeter. One millimeter is about as wide as the line you would draw with a sharp pencil. A nanometer is a much smaller unit. One millimeter is equal to one million nanometers! An atom is less than a nanometer across, so a device like an STM or an AFM is an essential tool for scientists who want to visualize and pick up individual atoms.

Some nanotechnology researchers are developing new ways of using various types of STMs and AFMs. Biologists can use a special type of AFM to look at proteins and other compounds one molecule at a time. Computer makers can produce super-miniature computer circuits. Medical researchers can examine how a particular medicine affects specific cells. Chemists and materials scientists are using nanotechnology techniques to develop completely new substances that have never before been made.

One of the problems with nanotechnology is that it is difficult to use “big” machines to make such incredibly tiny structures. So some engineers are working on designing “nanomachines.” These extremely tiny machines might someday be able to build very, very tiny robots called “nanobots.”


One nanobot would be too small to get a job done quickly all by itself. However, if millions of nanobots could work together, they might be able to do amazing things. Researchers think that teams of nanobots might be able to do microscopic surgery inside a patient’s body. Some groups of nanobots might be programmed to build objects by arranging atoms so precisely that there would be no waste. Other nanobots might even be designed to build more nanobots to replace those that wear out!

Compared to other areas of science, like chemistry and biology, nanotechnology is a very new area of research. Working with such small things is still very slow and difficult work. However, as the science of nanotechnology continues to develop, researchers will certainly find faster and easier ways to manipulate very small structures, including individual atoms.

1.5 Activity1. You will need the following materials:

• A firm object, such as your text book • A soft object, such as a small pillow or cotton ball• A pen• A piece of paper• A blindfold


This exercise will give you some idea as to how an STM operates.

Place the hard object on a table (or other flat surface) where you are comfortable writing.

Set the paper on the table next to the object. If you are right-handed, you will want the paper to the right of the object. If you are left-handed, you will want the paper to the left of the object.

Take the pen, and place it near the paper where you can easily find it and pick it up.

Take the blindfold, and place it over your eyes.

With your non-writing hand, feel the surface of the table until you touch the book or firm object.

Now take your index finger, and point it downward toward the object on the table. Your index finger is your “stylus.”

Move your finger (horizontally) over the object in a straight line, and at the same time, record with your writing hand what your feeling hand is touching. Draw just the first line of the object your finger is touching.

Next, move your finger slightly downward, and going in the opposite direction, scan your second line.

Repeat your scans until you reach the bottom of the object.

Repeat steps one through nine with the soft object and a new piece of paper.


Questions

1. How well do your drawings represent the real objects?

2. What are some of the problems you found when trying to “image” the objects in this way?


3. Based on your observations that you made with your “human STM,” list some of the problems that you think an actual STM might encounter.

4. Based on your observations that you made with your “human STM,” think about some ways that you might solve some of the problems you encountered.

real science-4-kids...telescope, much of what we have discovered about the universe would still be...

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