Science Tricks

8/10/2019 Science Tricks

1/9

Colour Changing Milk

WHAT TO DOPour some milk into the quarter plate. Now add a few drops of the food colour into the

bowl close to each other. Once this is done, take the cotton swab and dip it in the liquid detergent

and then dab the swab in the middle of any of the colour drops.

WHAT HAPPENS

There is a huge explosion of color when the swab dipped in liquid soap comes in contact with the

added food color. The food color which was just a few drops when added initially, is all over the

quater plate. You see a huge fusion of colours and this continues for quite sometime.

WHY THIS HAPPENS

Milk is made up of water, minerals, vitamins, proteins, and tiny droplets of fat. Soap breaks up thefat globules and weakens the chemical bonds of proteins.

Materials

A quarter plate

Milk

Food Colour (2-3 variants)

A cotton swab

Liquid Detergent

TRY THISReplace the milk with water and follow the same steps again. The results are not the

same. Can you tell why?


2/9

Burning Money Chemistry Demonstration

The burning money demo is a neat 'magic trick' that illustrates the process of combustion, the

flammability of alcohol, and the special qualities of the material used to make currency.

Scientific Concept behind Burning Money

A combustion reaction occurs between alcohol and oxygen, producing heat and light (energy) and

carbon dioxide and water.

C2H5OH + 4 O2-> 2 CO2+ 3 H2O + energy

When the bill is soaked an alcohol-water solution, the alcohol has a high vapor pressure and is

mainly on the outside of the material (a bill is more like fabric than paper, which is nice, if you've

ever accidentally washed one). When the bill is lit, the alcohol is what actually burns. The

temperature at which the alcohol burns is not high enough to evaporate the water, which has a high

specific heat, so the bill remains wet and isn't able to catch fire on its own. After the alcohol has

burned, the flame goes out, leaving a slightly damp dollar bill.

Here is what you need to perform the burning money demonstration:

dollar bill (higher denomination if you're brave)

tongs

matches or a lighter

salt (or one ofthese chemicals if you want a colored flame)

solution of 50% alcohol and 50% water (you can mix 95% alcohol with water in a 1:1 ratio, if

desired)

Here's how to perform the burning money demonstration:

1. Prepare the alcohol and water solution. You can mix 50 ml of water with 50 ml of 95-100% alcohol.

2. Add a pinch salt or other colorant to the alcohol/water solution, to help produce a visible flame.

3.

Soak a dollar bill in the alcohol/water solution so that it is thoroughly wet.

4. Use tongs to pick up the bill. Allow any excess liquid to drain. Move the damp bill away from the

alcohol-water solution.

5. Light the bill on fire and allow it to burn until the flame goes out.
http://chemistry.about.com/cs/howtos/a/aa052703a.htmhttp://chemistry.about.com/cs/howtos/a/aa052703a.htm


3/9

Fireball Instructions

Fire is made up of light and heated gases from combustion. You can control the temperature of fire

by selecting a fuel that burns with a cool flame. If you pour the fuel onto a substance that won't burn,

you can make a fireball that you can hold in your hand or juggle. Here are written instructions for

making your own handheld fireballs. There is also astep-by-step video tutorial of this fire project if

you would like see what to expect.

Materials Needed to Make Fireballs

2" x 5" strip of cotton cloth (like from a t-shirt)

100% cotton thread

needle

naphtha lighter fluid (e.g., Ronsonol)

match or lighterHow to Make a Fireball

Thread the needle with cotton thread.

Tightly roll the cotton strip into a ball.

Pierce the ball with the needle and wrap the ball with the thread. End by running the needle

through the ball one more time and break off the thread.

Soak the ball with lighter fluid. Don't soak your hands.

Don't ignite the the fireball while you are holding it. Set the ball on a fire-proof surface. I used a

frying panfrom my kitchen.

If you want to hold the fireball, my recommendation is to pick it up with tongs and

carefully/slowly set it on your hand. That way you'll be able to tell if you can take the heat or not.

Once you gain some confidence, you can pick the fireball up using your fingers.

Safety Additional Information

It's best to use 100% cotton fabric and thread. If the fiber is synthetic (like nylon or polyester) it

might burn or melt, with unpleasant consequences.
http://video.about.com/chemistry/Handheld-Fireballs.htmhttp://chemistry.about.com/b/2008/01/06/is-it-safe-to-use-kitchen-glassware-for-chemistry.htmhttp://chemistry.about.com/b/2008/01/06/is-it-safe-to-use-kitchen-glassware-for-chemistry.htmhttp://video.about.com/chemistry/Handheld-Fireballs.htm


4/9

The 'trick' to this demonstration is the fuel. It needs to be naphtha or kerosene. I have had good

luck with Ronsonol and Zippo (not the butane stuff... read your ingredient list). Rubbing

alcohol (isopropyl alcohol) works, but it burns a little hotter.

It's pretty hard to blow the fireball out. You either need to blow hard or else suffocate the flame to

extinguish it. You can set a saucepan lid over the fireball.

The fireballs are reusable. Put them out when they run out of fuel or else the cotton will burn (you

can tell this is happening when the ball starts to blacken and produce sooty smoke). If you get to

the point where the cotton itself is burning, the fireball will be too hot to hold. Ideally you want to

extinguish the fireball before it consumes all of its fuel. Simply soak it in more lighter fluid and

relight it to reuse it.

Regarding holding these in your hand or doing tricks with them... the cone of the flame is hot,

especially above the ball, however, the fuel burns at a relatively low temperature. The flashpoint

of Ronsonol brand of naphtha is 6C or 43 F, with combustion mainly around 400F. To put

that in perspective, touching the fireball is a lot like touching a hot pizza right out of the oven

(except without the sticky cheese part).

Fireballs are great fun to make, but like all fire projects, use proper safety precautions and common

sense. Don't get burned or set your house or yard on fire. This is a project which requires adult

supervision.


5/9

Cloud in a Bottle Demonstration

Here's a quick and easy science project you can do: make a cloud inside a bottle. Clouds form when

water vapor forms tiny visible droplets. This results from cooling the vapor. It helps to provide

particles around which the water can liquefy. In this project, we'll use smoke to help form a cloud.

Cloud in a Bottle Materials

1-liter bottle

warm water

match

Let's Make Clouds

1. Pour just enough warm water in the bottle to cover the bottom of the container.

2. Light the match and place the match head inside the bottle.

3. Allow the bottle to fill with smoke.

4. Cap the bottle.

5.

Squeeze the bottle really hard a few times. When you release the bottle, you should see the cloud

form. It may disappear between 'squeezes'.

The Other Way to Do It

Ok, here's theideal gas law:

PV = nRT, where P is pressure, V is volume, n is number of moles, R is a constant, and T is

temperature.

If we're not changing the amount of gas (as in a closed container) then if you raise the pressure, the

only way for the temperature of the gas to be unchanged is by decreasing the container volume

proportionally. I wasn't sure I could squeeze the bottle hard enough to achieve this (or that it wouldbounce back) and I wanted a really dense cloud for the photograph so I did the not-as-child-friendly

version of this demonstration (still pretty safe). I poured water from my coffeemaker into the bottom

of the bottle. Instant cloud! (... and a slight melting of the plastic) I couldn't find any matches, so I lit

a strip of cardboard on fire, inserted it into the bottle, and let the bottle get nice and smoky (and
http://chemistry.about.com/od/factsstructures/ig/Chemical-Structures---W/Water.htmhttp://chemistry.about.com/cs/workedproblems/a/bl113003a.htmhttp://chemistry.about.com/cs/workedproblems/a/bl113003a.htmhttp://chemistry.about.com/od/factsstructures/ig/Chemical-Structures---W/Water.htm


6/9

melted more plastic... you can see the deformation in the photo). Dense cloud, no squeezing required,

though of course it still worked.

How Clouds Form

Molecules of water vapor will bounce around like molecules of other gases unless you give them a

reason to stick together. Cooling the vapor slows the molecules down, so they have less kinetic

energy and more time to interact with each other. How do you cool the vapor? When you squeeze the

bottle, you compress the gas and increase its temperature. Releasing the container lets the gas

expand, which causes its temperature to go down. Real clouds form as warm air rises. As air gets

higher, its pressure is reduced. The air expands, which causes it to cool. As it cools below the dew

point, water vapor forms the droplets we see as clouds. Smoke acts the same in the atmosphere as it

does in the bottle. Other nucleation particles include dust, pollution, dirt, and even bacteria.


7/9

Kid-Friendly Elephant Toothpaste Demo

The elephant toothpaste demo is one of the most popular chemistry demos, in which a steaming tube

of foam keeps erupting from its container, resembling a smooshed tube of elephant-sized toothpaste.

The classic demo uses 30% hydrogen peroxide, which isnotsafe for kids, but there is a safe version of this demonstration that is still very cool.

What You Need

empty 20-oz plastic bottle (or other container)

3% hydrogen peroxide solution (available at nearly any store)

packet of active yeast (from the grocery store)

liquid dishwashing detergent (such as Dawn)

warm water

food coloring (optional, but it looks nice)

Make Elephant Toothpaste

1. Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food

coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or

outdoors or some other place where you won't mind getting wet foam everywhere.

2. In a separate container, mix a packet of active yeast with a little warm water. Give the yeast

about 5 minutes to activate before proceeding to the next step.

3. When you are ready to do the demo, pour the yeast mixture into the bottle.

How It Works

Hydrogen peroxide (H2O2) is a reactive molecule that readily decomposes into water (H2O) and

oxygen:

2H2O2 2H2O + O2(g)

In this demonstration, yeast catalyzes the decomposition so that it proceeds much more rapidly than

normal. The dishwashing detergent captures the oxygen that is released, making foam. Food coloring

can color the film of the bubbles so that you get colored foam. In addition to being a nice example of a

decomposition reaction and a catalyzed reaction, the elephant toothpaste demo is exothermic, so heat

is produced.


8/9

How To Make a Fruit Battery

If you have fruit, a couple of nails, and wire then you can generate electricity to turn on a light bulb.

Learn how to make a fruit battery. It's fun, safe, and easy.

Here's What You Need

citrus fruit (e.g., lemon, lime, orange, grapefruit)

copper nail, screw or wire (about 2" or 5 cm long)

zinc nail or screw or galvanized nail (about 2" or 5 cm long)

holiday light with 2" or 5 cm leads (enough wire to connect it to the nails)

Make a Fruit Battery

1.

Set the fruit on a table and gently roll it around to soften it up. You want the juice to be flowing

inside the fruit without breaking its skin. Alternatively, you can squeeze the fruit with your

hands.

2. Insert the zinc and copper nails into the fruit so that they are about 2" or 5 cm apart. You don't

want them to be touching each other. Avoid puncturing through the end of the fruit.

3. Remove enough insulation from the leads of the light (about 1") so that you can wrap one lead

around the zinc nail and one lead around the copper nail. If you like, you can use electrical tape or

alligator clips to keep the wire from falling off the nails.

4. When you connect the second nail, the light will turn on!

Learn More

Citrus fruits are acidic, which helps their juice to conduct electricity. What other fruits and

vegetables might you try that would work as batteries?

If you have a multimeter, you can measure the current produced by the battery. Compare the

effectiveness of different types of fuits. See what happens as you change the distance between the

nails.

Do acidic fruits always work better? Measure the pH (acidity) of the fruit juice and compare that

with the current through the wires or brightness of the light bulb.


9/9

How To Perform the Smoking Fingers Trick

Make your fingers smoke when you rub them together and glow in the dark. All you need is a

matchbox and a way to burn the striker portion. There's also avideo of the smoking fingers project, if

you'd like to see what to expect.

Difficulty: Easy

Time Required: about a minute

Here's How:

1. Cut out the striker portion of a matchbox from a box ofsafety matches.Trim off any paper around

the striker.

2. Fold the striker in half, striker-sides facing each other.

3. Set the folded striker on top of the running cold water faucet or a refrigerated metal pan.

4. Use a lighter to set fire to the striker. Ignite both ends. Then run the lighter along the length of

the folded striker. It won't burn to ash, which is fine.

5.

Discard the burned striker.

6.

You will see a brown residue that has been deposited along the top of the faucet or metal pan. Run

your fingertip along the residue to pick it up.

7. Slowly rub your finger and thumb together. If you do this in the dark, your fingers will have a

greenish glow. Very, very cool.

Tips:

1. Wash your hands after doing this, and try to avoid breathing in the smoke. The trick probably

involveswhite phosphorus,which can be absorbed through your skin and is toxic.

2. If you don't have scissors, you can do this trick by tearing off the striker portion of the matchbox

with your fingers. It's just easier to cut out the striker, if you can.

3. You could use the matches in the matchbox, rather than a lighter, of course.

What You Need:

matchbox of safety matches

cold water faucet or chilled pan

scissors

lighter
http://www.youtube.com/watch?v=W8BtVdeEOkQhttp://chemistry.about.com/od/howthingsworkfaqs/f/howmatcheswork.htmhttp://chemistry.about.com/b/a/257746.htmhttp://chemistry.about.com/b/a/257746.htmhttp://chemistry.about.com/od/howthingsworkfaqs/f/howmatcheswork.htmhttp://www.youtube.com/watch?v=W8BtVdeEOkQ

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Science Tricks