Interesting Labs and Activities
Steel Wool generating heat (Characteristics of Electricity)
Supplies: Thermometer
Jar
Steel Wool Pad
Vinegar
Chemical reactions occur every day all around us. A chemical reaction is a process where one type of substance is chemically converted to another substance. That fizzling toilet bowl cleaner is a chemical reaction. The fire in your fireplace is another type of chemical reaction. The smoke that comes out of Dad's ears when you lose one of his favorite golf clubs is a result of a chemical reaction. OK, so maybe that's a bad example. This experiment demonstrates a chemical reaction that's fairly common all around us (and we don't have to touch Dad's golf clubs to make this one work).
1 - Put the thermometer in the jar and close the lid.
2 - Wait about 5 minutes and write down the temperature.
3 - Remove the thermometer from the jar.
4 - Soak a piece of steel wool in vinegar for one minute.
5 - Squeeze the vinegar out of the steel wool pad.
6 - Wrap the steel wool around the bulb of the thermometer.
7 - Place the thermometer and steel wool back into the jar and close the lid.
8 - Wait 5 minutes.
9 - Now take a look at the temperature.
What happened to the temperature? Are you surprised that it the temperature rose (sorry this experiment didn't produce any smoke but then again, you didn't get grounded either).
The vinegar removes any protective coating from the steel wool, allowing the iron in the steel to rust. Rusting is a slow combination of iron with oxygen. When this happens, heat energy is released. The heat released by the rusting of the iron causes the mercury in the thermometer to expand and rise.
Parent's Note. Chemical reaction is a process in which one substance is chemically converted to another. All chemical reactions involve the formation or destruction of bonds between atoms (atoms, made up of protons and neutrons in a central nucleus surrounded electrons, are the smallest particle of a
chemical element that can take part in a chemical reaction without being permanently changed) . Chemical reactions include the rusting of iron and the digestion of food. Most chemical reactions give off heat. For example, chemical reactions that occur in digestion give off heat that keeps our bodies warm and functioning.
Chemists use chemical equations to express what occurs in chemical reactions. Chemical equations consist of chemical formulas and symbols that show the substances involved in chemical changes. The chemical reaction for the rusting of iron shows that four atoms of solid iron react with three molecules of oxygen gas to form two units of solid rust. Experiments demonstrate that iron and oxygen react in these proportions in air at room temperature. Rust is the product, or result, of the reaction. Iron and oxygen are the reactants. The reactants are the substances that undergo chemical change.
Clone a Plant (The Power of Reproduction)
The purpose of this activity is to allow you to work with materials that will allow you to attempt cloning.
You will need to do the following:
Formulate a hypothesis.
Make observations and measurements.
Collect and record data using procedures designed to minimize error.
Report results honestly.
Construct a graph.
Summary:
You will make a hypothesis about plant propagation. Next you will attempt asexual plant propagation. This activity requires that you observe your cutting daily and make observations as needed (including drawing changes you observe at least once a week and measure any differences as they appear.) You should report measurement differences in a table showing the amount of the root growth each week.
Materials needed:
scissors
plant for cutting (coleus or creeping charlie are recommended)
small test tube or bottle
water
Safety concerns:
Students, be sure to keep all Chemical , Glass, and Sharp instrument Safety Rules that are specified by your teacher and in all general laboratory experiences.
Procedures:
* Fill test tube or bottle 2/3 full of water.
* Cut a 15 cm. length of stem from your assigned plant (with leaves still attached).
It is important to know which end of the plant stem was closest to the plant!
* remove leaves starting at the end of the plant stem that was closest to the plant - stopping when you have ONLY 2 leaves left on the plant. (See animated image on this page for visual demonstration of what to do.)
Insert plant stem into water of test tube
Check daily
Add water as needed to keep it at the same level.
Make observations daily...noting changes on your sheet
Once you see any roots growing, measure them once a week.
Draw your cutting once a week
Questions:
1. Why did your plant develop roots if it did?
2. Why did your plant not develop roots if it did not?
3. What part of the cell allowed it to develop roots?
4. What other organisms do you think would work for this type of an activity?
Chemical Vs. Physical Change (Atoms and Elements)
Purpose:
To be able to recognize both a physical and chemical change in different substances.
Materials:
3 test tubes Alcohol burner
1 test tube rack Goggles
1 test tube holder 1 rubber stopper
1 graduated cylinder or beaker
Substances needed:
Copper sulfate solution
Iron filings
Water
Baking soda
Barium Chloride
Sodium sulfate
Tiny spoons
Procedure:
Bring the materials listed for each student or group to your work area. You will get other materials as you go through the lab.
Do the following experiment:
Put 1/2 spoonful of iron filings in a test tube.
Measure 5 mL. of copper sulfate solution (rinse out the cylinder after measuring)
Pour the copper sulfate into the test tube with the iron.
Gently heat the two until you see bubbles then stop.
Place the test tube in the rack to cool.
Answer the question below after the test tube has cooled for a couple of minutes.
After you have answered the questions, dump the contents of the test tube into the waste container - use the test tube holder to do this. Wash and rinse the test tube.
Questions for Experiment B:
Describe the materials before you mixed them.
Iron filings -
copper sulfate solution -
Describe the materials after you mixed and heated them. (How did they change?)
Was this a physical or chemical change? Why?
Do the following experiment:
Put one spoonful of baking soda into a test tube
Add 10 mL of water to the test tube
Put a rubber stopper in the test tube and shake vigorously.
Answer the questions below.
After you have finished the questions, dump the contents of the test tube into the sink. Wash and rinse the test tube.
Questions for Experiment C:
What happened to the baking soda after shaking it with the water?
Did you notice any temperature change after mixing?
Without tasting it, do you think the mixture would taste different than plain water?
Do you think the particles of sugar and water are still particles of sugar and water?
Was this a physical or chemical change? Why?
Do the following experiment:
Measure 5 mL of barium chloride and put it into a test tube.
Rinse out the graduated cylinder with water
Measure 5 mL of sodium sulfate solution and add it to the barium chloride
Put the test tube in the rack and allow to stand for a couple of minutes.
Answer the questions below.
After you have answered the questions, dump the contents of the test tube into the waste container.
Wash and rinse out the t est tube.
Questions for Experiment D:
Name two physical changes that occurred when you mixed the barium chloride and the sodium sulfate.
Was something new formed? If so, describe what the new substance looked like.
Was this a physical or chemical change? Why?
Complete this section after you have done the entire lab and cleaned up your station.
In which case are particles actually changed into different particles; a physical or chemical change?
Can a chemical change sometimes lead to a physical change? Give an example from this lab.
In which experiment(s) (B, C or D) did you:
form a solid from two liquids?
observe only a physical change?
observe a color change?
work with metal?
Explain why dissolving something in water is a physical change.
Triangluation (Exploration of the Universe)
Objective:
To understand the practical and mathematical techniques used to triangulate a position.
Minimum Facilities Required:
A large open room (gym or multipurpose room, for example) or field
A noise source that doesn't have to be plugged in (e.g., castanets)
Two screens that won't impede sound (cloth or paper...)
Markings (with chalk...) on the walls or floors of the room indicating a letter/number grid
Gridded paper representation of the room grid.
Large sheets of paper, pencils, rulers, protractors (optional)
Organization:
The class is organized into three equally sized groups. One group is assigned to be the noise source (NS). The other groups are each assigned to a Triangulation Station (TS), which are set up behind screens at consecutive corners of the room (the long side of the room is best). The students at the TS have a diagram of the room which is made out as a lettered/numbered grid.
Procedure:
The NS students form a line, more or less equally spaced, and more or less straight (to start with, you can try with curves later). They will toss the noise source from one to the other from one end of the line to the other with each toss at a time signal from the facilitator. This should be done slowly at first. The line should be invisible to the TS teams behind their screens.
In the TS teams, one or two students are chosen as antennas. When they hear a noise, they turn around to be able to hear it evenly out of both ears. (Note that a more advanced group could create equipment to do this using directional microphones and a suitable meter). The teams are challenged to find a way of using this information to figure out where the noise is on the grid, and after a few observations, to be able to call out the location where the noise will come from next. The walkie talkie helps the TS groups communicate their findings to each other - or they may use runners. They may also create a coordinated observation team at a command post that has the information relayed to it from both stations. The goal is to use information gathered at two Triangulation Stations to "triangulate" the location of the noise source.
For groups that respond well to competition, the NS group wins if they get the noise all the way to the end of the line. The TS group wins if they can correctly call out the grid square where the noise will go next.
Teams should rotate so that they all get the chance to be in each position. Ideally, a discussion of the technique they used to record and extrapolate the information can assist them in being more efficient with it on subsequent tries. Once the students get good at this, the speed of the noise toss, or the complexity of the trajectory can be increased.
Tie-in to Earth:
Triangulation techniques are used in surveying and mapping, tracking of aircraft and missiles, and other efforts to locate any emitting object. They can help in finding downed aircraft or lost ships that can still transmit radio signals.
