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Author: M. Rae Nelson
Editor: Kristine Krapp
Date: 2010
Document Type: Topic overview; Experiment activity
Length: 2,253 words
Content Level: (Level 3)
Lexile Measure: 1040L

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Nanotechnology is a relatively new field of science that makes more headlines every year. It is a field that focuses on the small--the extremely small. In nanotechnology, people manipulate atoms and molecules to make new things. Those things can be materials or devices.

Throughout history, people have made new things from altering or combining substances that already exist. But nanotechnology works the opposite way. In nanotechnology, researchers develop a substance from the small to the large by manipulating the basic building blocks of matter. The result could be miniature materials or devices that have completely unique properties.

Science of the small

The basic building blocks of nanotechnologies are atoms and molecules. All substances are made up of molecules. A drop of water, for example, is made up of millions of water molecules. If you were to keep dividing the drop into smaller droplets, you would end up with one molecule. That one water molecule would have the same properties as the drop of water.

Molecules are made of atoms held together by chemical bonds. The water molecule consists of two hydrogen atoms and an oxygen atom. Diamonds are made up of a molecule of carbon atoms bonded together. Salt is made of the sodium chloride molecule, which is one sodium atom bonded to one chloride atom.

Atoms and molecules are so small that a new prefix was coined to measure them: nano. The prefix "nano" comes from the Greek word for dwarf. Nano represents one billionth and so one nanometer is one-billionth of a meter. That's about the size of one strand of the width of your hair split into about 50,000 pieces! It's also about the size of ten hydrogen atoms. Things on the nanoscale are generally between 1 and 100 nanometers. Proteins in our bodies, viruses, and some particles in the air are nanosized.

Seeing the small

In order to work on the nanoscale, researchers needed to be able to see images of atoms and molecules. In 1981, the development of a powerful microscope allowed people to visualize the nanoscale on metals. Called the scanning tunneling microscope (STM), the microscope magnifies images of the shapes of atoms on the metal's surface. Microscopes soon followed that allowed researchers to see images of atoms and molecules on other materials.

Nanotechnology is not about simply making devices smaller. The field uses the fact that nanosize materials can have different properties than their larger counterparts. Color, hardness, melting point, and conductivity are all some of the properties that can change as the material become nanosized. One physical characteristic that can lead to these changes is the increased ratio of the surface area to volume.

Surface area is all the area that is on the outside--surface--of the material. Volume is the amount of three-dimensional space taken up by a material. As a material shrinks, its surface area increases compared to its volume, In the nanosize, this ratio can increase dramatically, which can lead to different reactions. Gold nanoparticles, for example, can appear a reddish color and turn liquid at room temperature.

It is the arrangement of the atoms and molecules that gives materials its properties. Diamonds and the lead of pencils (graphite) are both made of up carbon molecules. In diamonds, the arrangement and bonds of the carbon atoms make it hard and clear. Graphite is dark and relatively soft. If researchers can pluck individual atoms and decide how to arrange them, they can determine the property of the material. One nanoscale material that was discovered in 1991 is also made of pure carbon. Carbon nanotubes are threads of carbon and the arrangement of its carbon makes it light, flexible, and stronger than steel.

A nano-world of technologies

There are high hopes that research in nanotechnology will translate into many products and devices that will help people. The technology will affect a wide range of fields, including transportation, sports, electronics, and medicine. Some of the current and future possibilities of nanotechnology includes:

  • Medicine: Researchers are working to develop nanorobots to help diagnose and treat health problems. Medical nanorobots, also called nanobots, could someday be injected into a person bloodstream. In theory, the nanobots would find and destroy harmful substances, deliver medicines, and repair damage.
  • Sports: Nanotechnology has been incorporated in outdoor fabrics to add insulation from the cold without adding bulk. In sports equipment, nanotech metals in golf clubs make the clubs stronger yet lighter, allowing for greater speed. Tennis balls coated with nanoparticles protect the ball from air, allowing it to bounce far longer than the typical tennis ball.
  • Materials Science: Nanotechnology has led to coatings that make fabric stain proof and paper water resistant. A car bumper developed with nanotechnology is lighter yet a lot harder to dent than conventional bumpers. And nanoparticles added to surfaces and paints could someday make them resistant to bacteria or prevent dirt from sticking.
  • Electronics: The field of nano-electronics is working on miniaturizing and increasing the power of computer parts. If researchers could build wires or computer processing chips out of molecules, it could dramatically shrink the size of many electronics.

Guarding the nano-future

Much like other new technologies, nanotechnology has raised concerns and ethical questions. If devices become nanosize, people would not be able to see them. There is some concern these "invisible" devices could cause harm.

If nanobots are developed, researchers would want them to self-replicate like the cells in our body. These nanobots could potentially do many amazing things, such as pull trash apart into its microscopic molecules. But one question is what happens if there is a problem. What if nanorobots programmed to disassemble trash started taking apart other items? And what if these nanorobots multiplied endlessly?

So far, nanobots are only theoretical and years in the future. The field of nanotechnology promises many future benefits, and people are working to develop guidelines that will help us deal with potential problems.

Words to Know

The smallest unit of an element, made up of protons and neutrons in a central nucleus surrounded by moving electrons.
The force that holds two atoms together.
Control experiment
A set-up that is identical to the experiment but is not affected by the variable that will be changed during the experiment.
An idea in the form of a statement that can be tested by observation and/or experiment.
The smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms.
A nanoscale robot.
One-billionth of a meter.
Technology that involves working and developing technologies on the nanometer (atomic and molecular) scale.
Scanning tunneling microscope
A microscope that can show images of surfaces at the atomic level by scanning a probe over a surface.
Surface area
The total area of the outside of an object.
Something that can affect the results of an experiment.
The amount of space occupied by a three-dimensional object.

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Nanosize: How can the physical size affect a material's properties?


As materials become smaller, the surface area to volume ratio changes. Materials that are microscopic and nanosized have a much higher surface area to volume ratio compared to the same material you can see. Because you cannot see nano materials, in this experiment you will measure how the surface area to volume ratio changes the melting and freezing point of water. By freezing the water into large and small ice cubes, you can measure the surface area to volume ratio of each, and determine how long each size takes to melt and freeze.

For a cube, the surface area is the area of the six square. The area of one square is the length x the width, which are the same in a cube. The surface area (S) of the cube is the area of one side multiplied by six. If the length and width are represented by "a," then S = 6 x a x a.

The volume (V) of a cube is a x a x a. For a cube, the ratio of surface area to volume is then S/V, or 6/a (6:a).

Before you begin, make an educated guess about the outcome of the experiment based on your knowledge of surface area to volume ratio and water. This educated guess, or prediction, is your hypothesis. A hypothesis should explain these things:

  • the topic of the experiment
  • the variable you will change
  • the variable you will measure
  • what you expect to happen

A hypothesis should be brief, specific, and measurable. It must be something you can test through observation. Your experiment will prove or disprove your hypothesis. Here is one possible hypothesis for this experiment: "The cubes with the smaller surface area to volume ratio will melt and freeze faster."

In this case, the variable you will change will be the surface area to volume ratio, and the variable you will measure will be the time it takes for the ice to freeze and melt. You expect a shorter freezing and melting time for the smaller ice than the larger ice cubes.

What Are the Variables?

Variables are anything that might affect the results of an experiment. Here are the main variables in this experiment:

  • the size of the ice cubes
  • the material of the ice tray
  • the material the ice melts on
  • the temperature of the freezer
  • the room temperature

In other words, the variables in this experiment are everything that might affect the melting and freezing of the ice.

Level of Difficulty

Easy/moderate (there is simple math involved).

Materials Needed

  • conventional, large ice cube trade
  • mini ice-cube tray (available at party stores)
  • 2 plates
  • freezer
  • clock with minute hand
  • toothpicks or other small pointy object
  • ruler with centimeters

Approximate Budget



Approximately 3 hours.

How to Experiment Safely

There are no safety issues in this experiment.

Step-by-Step Instructions

  1. Pour water into at least three of the cubes in both the large and small ice cube trays.
  2. Place the trays in the freezer. Time for 30 minutes and poke each with a toothpick. If one set of ice cubes are frozen, note the time and leave them both in the freezer. Check back every five minutes until both sets are frozen and note the time for each. If neither ice cube tray is frozen solid, leave the trays in the freezer and check back every five minutes.
  3. When all the ice cubes are frozen solid, remove them from the trays. On one of the large and mini ice cubes, use the ruler to measure the dimension for a side of each. Round off the measurement and note.
  4. Place two large ice cubes on one plate, and two mini ice cubes on the second plate. Make sure the ice cubes are not touching. Set the plates aside and wait at least 30 minutes.
  5. Continue checking on the cubes at regular intervals. Note when the two small cubes and the two large cubes have completely melted.

Summary of Results

Was your hypothesis correct? Did the mini cubes melt and freeze faster than its larger counterpart? Rounding off the measurements, you can calculate the surface area and volume of the large cube and the small cube. How do the different surface area to volume ratios relate to the melting and freezing point?

Troubleshooter's Guide

This experiment is straightforward and you should not have any major issues. The freezing time may vary from the protocol depending upon the temperature of the freezer and the size of the cubes. The melting time will also vary depending upon the size of the cubes.

Change the Variables

If you want to vary this experiment, you can freeze water and melt the cubes in extreme size differences. How would a pan of water compare to an ice cube? You can also change the substance and look at surface area to volume ratios in solid substances, such as salt or sugar.

Sidebar: HideShow


Nanosize Substances: How can the physical size affect the rate of reaction?


One reason that nanosize substances may behave differently than the macrosize is due to the rate of reaction. Nanosize substances have a larger surface area compared to its larger counterpart. In this experiment, you will look at how increasing the surface area of a substance can affect its rate of reaction. You can use an antacid tablet and water. When antacid tablets react with water, the reaction produces carbon dioxide. In an enclosed container the carbon dioxide gas will push on the container and force its "top" into the air.

You can compare the rate of reaction between a whole antacid tablet and two varying sizes of the crushed tablet. One tablet will be broken into chunks and the other will be crushed, which will result in more surface area. Before you begin, make an educated guess about the outcome of the experiment based on your knowledge of surface area to volume ratio and water. This educated guess, or prediction, is your hypothesis. A hypothesis should explain these things:

  • the topic of the experiment
  • the variable you will change
  • the variable you will measure
  • what you expect to happen

A hypothesis should be brief, specific, and measurable. It must be something you can test through observation. Your experiment will prove or disprove your hypothesis. Here is one possible hypothesis for this experiment: "The greater the surface area, the faster the rate of reaction."

In this case, the variable you will change will be the surface area, and the variable you will measure will be the time it takes for the carbon dioxide to pop the top.

What Are the Variables?

Variables are anything that might affect the results of an experiment. Here are the main variables in this experiment:

  • the size of the ice cubes
  • the brand of antacid tablet
  • the size of the antacid tablet
  • the amount of water
  • the temperature of the water

In other words, the variables in this experiment are everything that might affect the rate at which the reaction occurs.

Level of Difficulty


Materials Needed

  • 6 antacid tablets
  • 2 pieces of paper
  • spoon or any hard object
  • 3 film canisters (35 mm film) with lids that fit on the inside (as opposed to snap on the outside of the canister); you could also use 1 canister and rinse it out after each use
  • watch with minute hand
  • helper
  • outside area or clear, inside area than can get messy

Approximate Budget



Approximately 15 minutes.

How to Experiment Safely

Step back quickly when you put the top on the canister so that it does not hit you. This experiment can be messy. If possible, work outside or in an area that is easy to clean.

Step-by-Step Instructions

  1. Fill all three canisters half full with water that is about room temperature. (If you only have one canister, fill a cup with water and allow it to get to room temperature before pouring it in the canister.)
  2. Go to the area where you want to set the canister down to time the reaction. As soon as you place the tablet in the canister, have your helper begin timing.
  3. Drop a whole antacid tablet in the canister. (Your helper should start timing now.)
  4. Quickly, snap on the top and set the canister down with the top on the bottom.
  5. When the reaction occurs and the canister flies into the air, make a note of the time.
  6. Place the second tablet on a piece of paper. Use a hard object, such as a book, to break the tablet into chunks. Carefully, drop the chunks into the second canister. Start timing! Firmly, place the top on the canister, flip it so the top is on the bottom and note the reaction time. Repeat this step with a crushed tablet. You will need to fold the paper and pour the crushed antacid into the container.
  7. Repeat each of the trials. If one reaction time is far off from the same tablet size, you may want to repeat the trial a third time until you can get repeatable results.

Summary of Results

Look at the reaction times for each of the three tablets with different surface areas. How does the amount of surface area relate to the reaction time?

Was your hypothesis correct? Write a summary of your results, including how this experiment relates to nanostructures and substances.

Troubleshooter's Guide

Below is a problem that you may have during this experiment and a way to remedy the problem.

  • Problem: The times for the two trials that were the same surface area were not at all close.
  • Possible cause: You may have used different water temperatures. Warmer water can speed up a reaction. Try setting aside a large container of water. Wait for the water to come to room temperature and then use this water for all your trials.

Change the Variables

Here are some ways you can vary this experiment:

  • Change the temperature of the water.
  • Change the amount of water.
  • Use a different substance to measure the rate of reaction, such as sugar and dissolving rates.

Sidebar: HideShow

Design Your Own Experiment

How to Select a Topic Relating to this Concept

Nanotechnology is a wide and growing field that may be incorporated in materials and technologies you use. Most likely, it could be in a car you use, sunscreen, or even clothes you wear. You may want to look up products that were developed with nanotechnology and see if the products are familiar or readily available.

Check the Further Readings section and talk with your science teacher to start gathering information on questions that interest you about nanotechnology.

Steps in the Scientific Method

To do an original experiment, you need to plan carefully and think things through. Otherwise, you might not be sure what questions you're answering, what you are or should be measuring, or what your findings prove or disprove.

Here are the steps in designing an experiment:

  • State the purpose of--and the underlying question behind--the experiment you propose to do.
  • Recognize the variables involved, and select one that will help you answer the question at hand.
  • State a testable hypothesis, an educated guess about the answer to your question.
  • Decide how to change the variable you selected.
  • Decide how to measure your results.

Recording Data and Summarizing the Results

Think of how you can share your results with others. Charts, graphs, and diagrams of the progress and results of the experiments are very helpful in informing others about an experiment.

Related Projects

To experiment in nanotechnology, you can find products that are made using nanotechnology and compare those products to others. Some papers and clothing have a nanotech surface. Aside from surface area to ratio, you can experiment with other properties that make nanosize materials different than their larger counterparts.

There are also many research projects you can do in nanotechnology. You can conduct a project on the major breakthroughs in the field or focus on one breakthrough, such as microscopes. You can also investigate the development and consequences of nanotechnology products in a certain field, such as medicine or sports equipment. Ethical issues and questions in the field of nanotechnology is another area of research.

Source Citation

Source Citation   

Gale Document Number: GALE|CV2644200093