A Bubble of Water

Theme: God continually watches over his universe and keeps it operating through his physical laws.

Bible Verse: [God is] upholding all things by the word of His power. (Hebrews 1:3)

Materials Needed:

• Pennies

• Eyedroppers

• Water

• Paper towels

Bible Lesson

In science classes we often describe the laws of nature. In truth, however, they are God’s laws. They were established at the creation to make our world dependable and fit for life. We also find that the laws of gravity, motion, and energy operate everywhere in space. That is, we live in a universe where God’s fingerprint of planning is obvious even in faraway places.

If our universe had formed by chance or accident, there would be no certainty that it would continue for another instant. In contrast, our Bible verse gives assurance of God’s continual control over nature. It is this promise that makes science research and discovery possible.

Science Activity

Our activity shows one small but essential part of nature called surface tension. Each participant is given a penny, an eyedropper, a small container of water, and a table or flat surface to work on. The object is to see how many drops of water can be placed on the face of the penny before water overflows the side. (Any kind of straw or squeeze bottle that releases single drops would work instead of eyedroppers.) The surface tension or stickiness of water results in a rounded bead of water on the penny. As water drops are carefully added, the growing bubble or “skin” of water will rise and wobble. The water drops will hold together in an impressive bubble. Eventually, gravity overcomes the water’s surface tension and a small spill occurs. Have paper towels nearby for the cleanup. If time permits, have participants count the drops as they are applied to compete with each other for the highest number.

Surface tension allows many drops of water to remain on a penny.

Science Explanation

Water has one of the highest surface tensions of any common material. In the following comparative list, only mercury has a greater surface tension.

	Liquid	Relative Surface Tension
	Ethyl alcohol	.29
	Ammonia	.31
	Soapy water	.33
	Sulfuric acid	.73
	Blood	.80
	Water	1.0
	Mercury	6.5

This high surface tension of water has many practical benefits:

Water climbs up the narrow capillary tubes of plants and trees to water the upper leaves.

Watery fluids cling to our bone joints and also our eyes for constant lubrication.

Surface tension causes raindrop formation.

Soil remains moist as water drops cling to each other and to soil particles.

Water molecules are drawn toward each other because of an attractive electrical force. Slightly positive hydrogen atoms in one water molecule are attracted to negatively charged oxygen atoms in surrounding molecules. This forms a hydrogen bond that is responsible for many of water’s special properties.

For further study, add a drop of soap solution to a penny that is covered with water. Soap reduces surface tension, causing the water to quickly spill off the coin. This soap property helps water droplets separate so they can move inside cloth fabric during clothes washing. The water then dissolves dirt and particles within the material fibers and carries them away.