Tuesday, October 6, 2009

ACID INDICATOR

MATERIALS

Bromthymol blue (BTB) (available in supply catalogs)
A cup (a glass, or even a test tube)
Drinking straw

PROCEDURE

1. Add 1-2 drops BTB to 15 ml of water.
2. Using the straw, blow into the BTB solution.
3. Observe.

EXPLANATION

BTB is an indicator for acid. Carbon dioxide, when mixed with water, forms a weak acid. When acid is present, the blue BTB will turn yellow. When you blow out, you are blowing out carbon dioxide. You should see the solution turn yellow.
BTB is inexpensive and easily obtained in supply catalogs. You will find that you will use it for more than one experiment.

SAFETY PRECAUTIONS

BTB is a stain and will stain clothing. Always have an adult present and remind children not to put any solutions into their mouths.

Saturday, May 30, 2009

LET'S MAKE FOSSILS

MATERIALS

1/2 cup cornstarch
1 cup baking soda
5/8 cup cold water
wax paper
leafs, bones, shells

PROCEDURE

Have an adult stir first 3
ingredients over medium heat.
Shape into about a dozen one inch balls.
Flatten a ball onto wax paper.
Press a leaf, bone, or shell into the dough.
Remove the leaf, bone or shell, leaving
an imprint.
Allow to dry.

EXPLANATION

Fossils are found in sedimentary rocks.
Prerequisites for fossils are:
1) organisms must be hard, such as bones,
teeth, shells
2) they must be in an oxygen-free environment,
away from predators
3) they must be in favorable heat and pressure
conditions

Four types of fossils:
1. Petrified fossils
Examples are porous wood or bones. Minerals seep
in, turning the porous material into stone.
2. Carbon fossils
Water and gas are squeezed out of the material,
leaving only carbon.
3. Molds and casts
The material leaves a hole in the rock in the
exact shape of the original specimen.
4. Trace fossils
Signs are left behind by an organism.
Examples: footprints, nests, burrows

Thursday, March 26, 2009

GOOEY STUFF

MATERIALS

Half of a box of cornstarch (227grams)
200 ml water (7/8 cup)
Few drops food coloring
Container with airtight lid
Metal spoon

This mixture should stay fresh for about two weeks if stored in refrigerator in an airtight container.

SAFETY PRECAUTIONS
Always remind your children not to taste anything during a science experiment.

PROCEDURE

1. Mix the cornstarch and water together until texture is smooth. Add green food coloring. Have child dig into it with their hands, feeling the texture and observing the characteristics of this weird mixture.
2. Have your child describe to you the characteristics and make a list of them. They may notice it is both “runny” and “powdery” at the same time. How can that be? Encourage description and discussion.
3. Ask: What do you think will happen if you strike the “gooey stuff” with a metal spoon?


Always have the child predict what will happen, then actually do it, then discuss what they observed actually happened.


EXPLANATION

The liquid particles of the water are scattered throughout the solid particles of the cornstarch. The particles of one are dispersed throughout the other. Therefore, each substance, the liquid and the solid, retains its own individual characteristics (properties.) Hence, this “gooey stuff” has the properties of a liquid and a solid simultaneously- runny and powdery at the same time. Weird!

Thursday, January 22, 2009

MAGNETIC MUSCLE

MATERIALS

Scissors
Ruler
String
One Bar magnet
Masking tape
Box of about 100 small paper clips
Large bowl

PROCEDURE

1. Cut 2 pieces of string, each about 1 meter long.
2. Tie one end of each string to each end of the bar magnet.
3. Tape the free ends of the strings to the top of a doorframe. Adjust height as necessary.
4. Ask, “Which part of the magnet do you think will attract paper clips the strongest?” Then, raise bowl full of paper clips so that the magnet touches the paper clips.
5. Slowly lower the bowl.
6. Observe what part of the magnet attracts the most clips.

EXPLANATION

Most of the clinging paper clips should be concentrated at or near the 2 ends of the magnet. All magnets are surrounded by an area called a magnetic field. This force moves from the north pole of the magnet, around the side, and into the south pole of the magnet. These magnetic force lines are closest together at the 2 poles, which give the 2 poles the strongest magnetic attraction.

Wednesday, January 14, 2009

SOUND WAVES

This activity is easy to set up, and gives the student a visual about how sound waves move.

MATERIALS

5 marbles
Flat surface

PROCEDURE

1. Line 4 marbles up in a straight line on a flat surface, close enough that they are touching each other.
2. Shoot the 5th marble so that it hits the end marble.
3. Observe. Discuss.

EXPLANATION

Each marble contains a certain amount of energy called Potential Energy. When the 1st marble hits the second marble, the Potential Energy is converted to Kinetic Energy (energy of movement) and passes its energy on down the line to the third marble, and so forth. This passing of energy from one marble to the next illustrates the way a sound wave is produced.

Monday, August 25, 2008

A THREAD OF CRYSTALS

This activity takes a few days, up to a week, after the setup to grow the crystals. The result is a variety of beautiful crystals for students to observe and compare.

MATERIALS

Gather as many of the following substances as you can: Epsom salt, Alum (found in the spice section at the grocery store), Borax (found in the laundry section in your grocery store), Rock salt
Hot water
A glass jar for each type of crystal grown
Cotton thread
A pencil for each type of crystal grown (or Popsicle stick)
Adult

SAFETY PRECAUTION
Use appropriate safety precautions when using hot water. Have an adult present for use with hot water.

PROCEDURE

1.With an adult, heat water on stovetop or microwave. Pour into glass jar.
2.Add your substance (Alum, Borax, Epsom salt, or Rock salt) to the hot water until you cannot stir in any more substance. This is a saturated solution.
3.Pour the above solution off into a clean jar. Leave behind any undissolved salt.
4.Tie a thread to a pencil (or Popsicle stick) and suspend the thread into your solution. Bridge the opening of the jar with the pencil.
5.Label your jar as to the type of solution.
6.Cover the jar with a piece of paper towel to control the rate of evaporation. Set aside in a place where it will not be disturbed.
7.Repeat above procedure with each substance. You should have 4 jars, one for each type of substance used. Label each.
8.Observe daily. Record your observations. Draw what you see.

EXPLANATION

As the water evaporates, the substance will come out of solution and begin to grow on the thread. This process can take days, even a week. Each crystal will look different. All 4 of these substances are a type of salt: Alum salt, Borax salt, Epsom salt, and Rock salt. As the liquid cools and the water evaporates, some of the molecules in the substance move closer together and join in a repeating pattern. The crystal grows in size by adding more molecules in the same pattern. Each type of crystal has a unique pattern.

Tuesday, April 29, 2008

CHEMICAL REACTION

This is a fun and easy activity to do that involves
a chemical reaction. Your students will clean for
you, and they won't even complain!

MATERIALS

Tarnished pennies
Vinegar
Salt
Small bowl or jar

SAFETY PRECAUTION

Appropriate safety precautions to protect eyes while working with
vinegar should be used.

PROCEDURE

1. Place about ¼ cup (about 60 ml) vinegar into small bowl or jar.
2. Add about 2T (30ml) salt. Stir.
3. Add several tarnished pennies to the bowl. Leave one tarnished
penny aside to use for comparison.
4. Wait a few minutes. Ask, “What do you think will happen? Why?”
5. After a few minutes, remove the pennies.
6. Experiment with different amounts of vinegar and salt. Which
works best?

EXPLANATION

A chemical reaction occurred. Salt is sodium chloride. The chloride
from the salt combined with the hydrogen from the vinegar to form
hydrochloric acid, which cleaned the pennies.
You can use this formula to clean any copper or bronze object in your
home, or use especially formulated brass cleaner.

Wednesday, January 16, 2008

LET'S MAKE A HYGROMETER

When studying the weather, an easy science activity to do is make a hygrometer, which measures the humidity. This activity is best for homeschoolers because it requires an oven. The activity works great and is easy to do.

MATERIALS

Pine cones
Aluminum foil
Oven
Water
Bowl
Cake pan

PROCEDURE

1. Place pine cones in water in the bowl.
2. Wait 45 minutes. Then draw a picture in
your science journal of the pine cones,
observing their scales.
3. Transfer pinecones to cake pan which you
have lined with foil for protection.
4. With an adult, bake the cones on low heat
in the oven for 30 minutes.
5. Remove pan from oven. Now draw a picture
of the scales in your science journal. Label.

EXPLANATION

A hygrometer measures the humidity (moisture in
the air.) A pine cone makes a good hygrometer.
When the pinecones are wet, the scales close
up. When they are dry, they open.

Wednesday, December 19, 2007

pH INDICATOR

MATERIALS

Red cabbage
Sugar water
Baking soda
Vinegar
Cups (clear plastic, or paper)
Knife and pan
Stovetop

SAFETY PRECAUTIONS

Should be supervised by an adult due to the chopping with a knife and heating on a stovetop.

PROCEDURE

1. Chop a few leaves of red cabbage finely and place in pot. Cover with water, bring to boil, reduce heat, and simmer until solution is deep blue/purple.
2. Allow cabbage solution to cool. Strain into a jar. After the experiment is over, be sure to save this solution for other experiments. It saves well, covered, in the refrigerator. This is your indicator. If you wish, you may also take strips of white filter paper (such as a coffee filter cut into strips 2-3 inches long) and soak in the juice, and then let dry, to use as indicator strips to experiment with. Still save the juice, however.
3. Explain the term ‘indicator.’ (a substance that indicates if something is acidic or basic.)
4. Mix baking soda with a little water in a cup to make a baking soda/water solution. Label “baking soda”.
5. Pour a small amount of sugar water into another cup and label “sugar water”.
5. Pour a small amount of vinegar into a third cup and dilute with a little water. Label “vinegar”.
6. Ask, “What do you think will happen if we pour our cabbage juice/indicator into these cups?”
7. Add cabbage juice/indicator into each of the 3 cups, recording observations on the chart provided.
8. Discuss acids and bases and how they react with the cabbage juice indicator. Discuss neutral solutions and how they react with the indicator.

EXPLANATION

Cabbage juice is an indicator that indicates if a substance is acid, base, or neutral. If a substance is an acid, the cabbage juice (or strip) will turn pink or red. If a substance is a base, the cabbage juice will turn green or blue-green. If a substance is neutral, the cabbage juice/indicator will not change color. The vinegar is an acid and will turn pink. The baking soda is a base and will turn green.

Sunday, December 2, 2007

Gas Matters

Kids love this dynamic demonstration. Easy and effective!

MATERIALS

Baby food jar
Carbonated water (or clear carbonated soda)
1 tsp table salt

PROCEDURE

1. Fill baby food jar ½ full with carbonated clear liquid.
2. Ask, “Do you think carbon dioxide gas is considered ‘matter’?” “How do you define ‘matter’?” (Has mass and takes up space.)
3. Ask, “What do you think will happen if we add some salt to this jar?”
4. Add 1 teaspoon of table salt to the jar. Observe. Ask, “Why do you think this happened?”

EXPLANATION

The bubbles in the carbonated liquid are full of carbon dioxide. Carbon dioxide gas takes up space. When you add the salt molecules, the salt molecules push the carbon dioxide molecules out of the way. When the carbon dioxide bubbles rise to the top, they bring small amounts of soda with them. Replacing a gas with another substance is called “effervescence.” Gas is considered ‘matter’ because it fulfills the two requirements: it takes up space, and, it has mass (weight).

Friday, November 2, 2007

THREE IN ONE

MATERIALS

Shaving cream
Magnifying glass
Penny
Small plate

PROCEDURE
1. Place a small amount of shaving cream on the plate. Describe it. Is it a solid, liquid, or a gas?
2. Gently, place the penny on top of the shaving cream. What happens? Is the shaving cream a solid, liquid, or a gas?
3. Rub the shaving cream between your fingers. What does it feel like? Does it act like a solid, liquid, or a gas?
4. Examine the shaving cream with the magnifying glass. What do you see? Does it look like a solid, liquid, or a gas?
5. Let the shaving cream sit out overnight. What does it look like now? Let it sit for a few more days. Does it change its state?



EXPLANATION

Some substances exhibit characteristics, or properties, of more than one state, or phase, of matter. Shaving cream feels like a liquid when you rub it between your fingers. It has gas bubbles in it. It keeps its shape and supports light objects and therefore acts like a solid. When you let it sit for a few days, the liquid evaporates and leaves a very thin solid and spaces where the gas bubbles were. The molecules of the gas, the solid, and the liquid, are dispersed throughout each other, each retaining its own properties. This is referred to as a ‘colloid’.

Wednesday, October 17, 2007

CLASSIFYING MATTER

MATERIALS

1 tray per team
At least 2 people
A variety of small objects found around the home (buttons, paper clips, etc.)
Paper towels

PROCEDURE

1. Arrange a variety of small household objects on a tray (about 40-50 items). Prepare one tray per team. A team may consist of 1-4 people. Have at least 2 teams.
2. Each team classifies the objects on its tray into just 2 groups. Do not tell the other team what properties are being used to classify the 2 groups.
3. Now, each team inspects the trays of the other teams and tries to guess how that team classified its matter (example, by color, by size, by material, etc.)
4. Return to your own tray. Cover one of the 2 groups with a paper towel. Now, classify the remaining objects into 2 groups.
5. Now, each team inspects the trays of the other teams and tries to guess how that team classified its matter.
6. Repeat steps 4 and 5 until you cannot classify any further.

EXPLANATION

This is a fun activity with valuable skills learned. Matter is classified according to its properties, in any way the children decide. Each classification system is as valid as the other. There are no wrong answers.
This can also be done with buttons if you happen to have a large collection of a variety of buttons that provide different shapes, colors, materials, number of buttonholes, etc.

Friday, October 5, 2007

MEASUREMENT

TEMPERATURE

MATERIALS

Cup or bowl with ice
Rock salt
Graph paper
Thermometer that reads Fahrenheit and Centigrade degrees
Timer

PROCEDURE

1. Place ice in cup, or bowl, and read the temperature. Record.
2. Sprinkle 1-2 tablespoons of rock salt on the ice. Start timing.
3. Read and record temperature every 30 seconds for 3 minutes (see the chart on the following pages.)
4. Try different bowls. Does the type of bowl (size, metal or plastic) change your answers? Change the amount of salt you added. Does this change your answer?
5. Graph your results with temperature as the ‘y’ axis, and time as the ‘x’ axis.
Have your parents help.

EXPLANATION

After addition of the rock salt, you will notice the temperature decreasing. This is why you add rock salt to the ice in an ice cream machine; it makes it colder which in turn makes it easier for ice cream to form.

Sunday, September 23, 2007

LET'S MAKE CLOUDS

MATERIALS

Glass jar with lid
Ice cubes
Hot water
Flashlight

PROCEDURE

1. Fill jar half-full with hot water*
(*have an adult do this)
2. Place lid upside down on top of jar
Wait a few minutes
3. Now place ice cubes on the lid
Observe. May darken room and shine flashlight
through jar for better viewing

EXPLANATION

You should see moisture condensing on
the sides of the jar, resembling clouds.
When the air is cooled by the ice cubes, the
water condenses and drops back down into
the water.
This is similar to water vapor cooling
in the air high above us, condensing into
clouds of raindrops, and dropping back down
to earth as precipitation.