biologia: more science fair projec tby mikayla vanden brenk

MIKAYLA VAN DEN BRENK & LAURA SOFIA GOMEZ

7ª

Vermont School Medellín

IF YOU MIX BUBBLES WITH ANOTHER SUBSTANCE, THEY WILL LAST LONGER

Colegio Gimnasio Vermont Medellín

Science

7 A

Mikayla van den brenk & Laura sofia gomez gomez

Medellín, Antioquia

February, 2013

If You Mix Bubble Mix With Another Substance, It Will Last Longer

Introduction….

Theoretical Background

Almost every kid loves to blow bubbles – and wishes that their bubbles don’t pop or evaporate so quickly! This science fair project will help to determine if adding other substances to a bubble solution can help the bubbles last longer. Testing was done by adding corn syrup, sugar water, and lemon juice the to the bubble solution. LALA

Bubbles are made of a solution containing soap and water. The structure of bubbles is very similar to a sandwich, because bubbles are made of a thin layer of water surrounded by two thin layers of soap particles, and air inside. As you blow a bubble, the air pushes on the sandwich, expanding layers of water and soap particles until they break apart, thus popping the bubble. But we will test which substance will increase the thickness of the bubbles the most, therefore increasing the time before the bubble pops.MIKY

When the soapy solution is stretched across a surface (the end of a bubble wand, for example), it forms a thin, filmy sheet with fairly low surface tension. As air fills the sheet, it takes on a spherical shape. This is because, as the solution stretches and the surface concentration of the soap drops, the surface tension rises.LALA To compensate for this increase in surface tension, the bubble forms into a shape that puts the least amount of stress on the surface layer. For any given volume, spheres have the lowest possible surface area. This means that the surface layer has to stretch the least when forming into a sphere.MIKY

Read more: How Bubbles Are Made | eHow.com

http://www.ehow.com/how-does_4912993_how-bubbles-made.html#ixzz2KhySKgXc

Hypothesis LALA

Soap bubbles made from solutions containing lemon will last longer MIKY

1. Objectives

a) If mixing other substances makes bubbles stronger

b) Which substances make bubbles the strongest

c) Which substances make the least difference

2. Materials and Reactives

MATERIALS	REACTIVES
3 EMPTY PLASTIC CUPS	300ml WATER
A BUBBLE BLOWING TOY	100ml LIQUID DETERGENT
1 STOPWATCH
A MEASURING BEAKER	10mg SUGAR
A WEIGHING SCALE	10ml LEMON JUICE
1 BLACK MARKER PEN

3. Procedure

1.    For this science fair project, the independent variable is the additive added to the bubble solution – soap, corn syrup, sugar and lemon. The dependent variable is the length of time the soap bubbles are able to last before bursting. This is measured with a stopwatch. The constants (control variables) are the room temperature and the mixing ratio of the bubble solution.

2.    Using the black marker pen, the 4 plastic cups are labeled as “soap”, “sugar” and “lemon”.

3.    Each cup is filled with 100ml of water. Another 20ml of liquid detergent is added to each cup and mixed with the water. Then, depending on the marking on the cups, 10 ml of corn syrup, sugar and lemon is added to each cup and mixed once more. The cup marked soap will be the control and it contains only a mixture of water and detergent.

4.    The bubble blowing toy is dipped into one of the plastic cups and a bubble will be blown. The stopwatch is started and it is observed how long the bubble lasts before it bursts. The experiment is repeated 5 times and the longest time clocked, is recorded in the table given below.

5.    Procedure 4 is repeated using the solutions in the other 3 cups. The longest time taken before the bubble bursts is clocked and the results recorded in the table below.