Over the past few years, TOPS volunteers and their teacher partners have developed numerous laboratory procedures and worksheets that have been used in Middle School science classrooms. These procedures are available to volunteers and web site guests in Adobe® pdf format files. Click on the blue button below for a specific procedure or copy this link to your browser for a complete list: https://www.dropbox.com/sh/pg6gem1fuowiwmz/AAAF8eqcauc9xHDakGIzyuIwa?dl=0
The importance of lab safety and the dangers of working with certain chemicals is provided in this lab safety demonstration procedure.
Balancing Chemical Equations
A worksheet that helps students learn to balance selected chemical equations from among synthesis, decomposition, single-displacement, and double-displacement types.
Boiling Water at Low Temperature
This activity enables students to explore the connection between pressure and boiling point by lowering the pressure.
Chemical Reactions that Produce Light
Chemiluminescence is a chemical reaction that produces light with little or no heat. Most students have seen this phenomenon in the from of “light sticks.” This procedure enables the volunteer to demonstrate an example of this reaction using luminol.
Flame Tests to Identify Elements
In this lab activity, students observe the color produced when the salts of four different chemical elements are placed in a flame.
Floating Pennies and Archimedes' Principle
This hands-on activity by the students enables them to float pennies in a plastic cup and to calculate the buoyant force acting upon it. They then compare the buoyant force with the weight of the cup and pennies to prove Archimedes Principle that the buoyant force on an object is equal to the weight of the fluid the object displaces.
This dramatic demonstration by a volunteer involves the oxidation of glycerol with potassium permanganate to produce white smoke and a violet flame.
Clues to a Chemical Reaction - Halloween Colors
A chemical change is demonstrated using the decomposition of hydrogen peroxide and the
simultaneous reduction of chromium. Students recognize the evidence for a chemical reaction by observing the formation of new substances by the formation of a gas, an increase in temperature and a rapid color change from orange to black.
Kinetic Theory and Graph Analysis
This exercise enables students to relate phase change to the kinetic theory and to interpret a graph showing temperature change.
Calculating Acceleration of Cars
Students calculate the acceleration of eight automobiles with data taken from published articles.
Simple Electrical Circuits
This demonstration by a volunteer helps students understand Ohm's Law and the relationship between power and current. A simple electrical circuit apparatus is used to pass an alternating electrical current through a hot dog held at its ends by two nails, which act as electrodes. The resistance of the hot dog enables it to heat up and cook.
Compare the Density of Ice and Liquid Water
This activity helps students understand that the forces of attraction between the hydrogen and oxygen molecules are greater in liquid water than in ice. Thus, there are more spaces between the molecules in ice than in liquid water, so ice is less dense than liquid water. Keywords: Ice Water Density
Chemical Reaction - Synthesis
This procedure describes a demonstration that enables students to observe a synthesis type reaction involving burning of the element magnesium with oxygen in the air to produce a new substance, magnesium oxide.
The Laws of Conservation of Mass & Definite Proportions
This demonstration by a volunteer involves the reaction between sodium bicarbonate (“baking soda”) and acetic acid (“vinegar”) to produce sodium acetate, water and carbon dioxide. A demonstration with a rigid bottle containing the reactants on a triple beam balance, proves that the mass of the products of a chemical reaction are equal to the mass of the reactants. The experimental procedure is available.
Accompanying the experimental procedure is a PowerPoint lesson with calculations that prove Lavoisier's Law of Mass Conservation and Proust's Law of Definite Proportions.
The Metric System
The metric system is reviewed and simple problems are presented. Metric scale units and a brief history of the temperature scales are also available.
The Concept of pH to Measure Acidity & Basicity
Starting with a batch of orange juice made from a can of frozen concentrate, students prepare four separate dilute solutions each with a different concentration and measure their pH using Precision pH Test Strips. Students then plot the data on semi-logarithmic paper to show that each whole value of pH above 1 is ten times less acidic than the next.
Determining Speed & Velocity
This exercise, which includes problems, helps students learn that Speed is a measure of how fast an object is moving or traveling, while Velocity is a measure of how fast an object is moving or traveling in a specific direction. Both speed and velocity include the distance traveled compared to the amount of time taken to cover this distance.
Chemical Reaction - Decomposition
Students observe the acid-catalyzed decomposition of common table sugar (sucrose). Students
recognize the evidence for a chemical reaction by observing the formation of new substances by a color change, increase in temperature, and the formation of a gas. The decomposition of white sucrose, catalyzed by concentrated sulfuric acid, results in the formation of a black solid, carbon, and a gas, water liberated as steam.
DNA from Strawberries
This hands-on experiment provides a good introduction to biology. After the teacher explains what DNA is and why it's important, students then extract and isolate DNA from strawberries.
Chemical Reaction - Precipitate Formation
In this simple demonstration, students are taught two clues to a chemical reaction: change in color and precipitate formation. When 100 ml of a 3% clear, colorless solution of silver nitrate is added to 100 ml of a 1% clear, colorless solution of sodium chloride, a white milky-like mixture is immediately formed and minutes later a heavy white precipitate of silver chloride settles to the bottom of the flask.
Periodic Table of the Elements Review
Students review the fundamentals that they learned about organization of the periodic table. This review consist of 25 questions including a chart where they fill in the period number, family names, number of family members, and number of energy levels.
Another activity that students enjoy is solving crossword puzzles. Students can use their textbook and online searches to learn the relationship between elements from the periodic table and their uses in products and everyday life . One puzzle focuses on the elements derived from stars (up to iron) while the other includes only the additional elements created in a supernova.
The Gauss Rifle: A Magnetic Linear Accelerator
This simple experiment uses a magnetic chain reaction to launch a steel marble toward a target at high speed. The device is relatively simple to build and the concept is easy to explain. Students learn about the relationship between kinetic energy and velocity.
The Electrolysis of Water
Another example of chemical change is water electrolysis, which shows both the decomposition of water and the synthesis of hydrogen and oxygen gases. This experiment requires a Hoffman Apparatus with platinum electrodes and a 12 volt DC power supply. Students are taught about the gain (reduction) and loss (oxidation) of electrons in an electrochemical reaction as well as the Law of Conservation of Mass.
A procedure for the demonstration of water electrolysis that uses a simple set-up is also available. The gases cannot be measured or collected, but students can see many more bubbles of hydrogen than oxygen being released from the electrodes.
Newton's Third Law of Motion
Students use a set of dowel pins, a small wooden cart with a rubber band and three blocks of wood, each with a different mass to see Newton's Third Law of Motion in action.
Students are introduced to the law of universal gravitation and asked to solve problems related to the concept.
Pennies Radioactive Half-Life Lab
Students use 100 pennies to create a graph of half-life that simulates the half life of radioactive isotopes.
Acknowledgement: Many thanks to Mrs. Hope Oliver and Michael Berwald, Bret Harte Middle School, San Jose, California, for creating and helping to improve many of the laboratory procedures described above.
TOPS of Santa Clara Valley
Teaching Opportunities for Partners in Science