I need to know a LOT of details on surface tension. I have a project due TOMORROW! Can anyone help me?

Question

my project is on surface tension. u kno the basics. water striders, plants sucking up water, water over the top of the cup....yeah....the basics

Answer 1

The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. This forms a surface "film" which makes it more difficult to move an object through the surface than to move it when it is completely submersed.

Surface tension is typically measured in dynes/cm, the force in dynes required to break a film of length 1 cm. Equivalently, it can be stated as surface energy in ergs per square centimeter. Water at 20°C has a surface tension of 72.8 dynes/cm compared to 22.3 for ethyl alcohol and 465 for mercury.

Surface Tension Examples:

Walking on water:

Small insects such as the water strider can walk on water because their weight is not enough to penetrate the surface.

Floating a needle:

If carefully placed on the surface, a small needle can be made to float on the surface of water even though it is several times as dense as water. If the surface is agitated to break up the surface tension, then needle will quickly sink.

Don't touch the tent!

Common tent materials are somewhat rainproof in that the surface tension of water will bridge the pores in the finely woven material. But if you touch the tent material with your finger, you break the surface tension and the rain will drip through. Soaps and detergents help the cleaning of clothes by lowering the surface tension of the water so that it more readily soaks into pores and soiled areas.

Clinical test for jaundice:

Normal urine has a surface tension of about 66 dynes/cm but if bile is present (a test for jaundice), it drops to about 55. In the Hay test, powdered sulfur is sprinkled on the urine surface. It will float on normal urine, but sink if the S.T. is lowered by the bile.

Washing with cold water :

The major reason for using hot water for washing is that its surface tension is lower and it is a better wetting agent. But if the detergent lowers the surface tension, the heating may be unneccessary.

Surface tension disinfectants:

Disinfectants are usually solutions of low surface tension. This allow them to spread out on the cell walls of bacteria and disrupt them. One such disinfectant, S.T.37, has a name which points to its low surface tension compared to the 72 dynes/cm for water.

Hope this helps. Good luck tomorrow.

HANK (Josh)

Answer 2

In physics, surface tension is an effect within the surface layer of a liquid that causes that layer to behave as an elastic sheet. This effect allows insects (such as the water strider) to walk on water, allows small metal objects such as needles, razor blades, or foil fragments to float on the surface of water, and causes capillary action. Interface tension is the name of the same effect when it takes place between two liquids.

Answer 3

Surface tension exists because it's the boundary between one things (the liquid) and another (the air above). Molecules of one kind attract each other (that's why solids stick together, and why liquids sorta do). Deep inside the liquid, there's attraction all around the molecule that's exactly the same. But at the surface, the attraction is only coming from the surface and beneath, not from the air above. See full explanation at the wiki link.

Answer 4

More details would have been helpful. Use water, its easy to work with and has great surface tension.

Answer 5

you're able to do this, cool test with baking soda and vinegar. not in basic terms a stupid volcano. additionally get a candle,journey, lighter, balloon, cup. one million. mixture alot of Baking Soda and Vinegar in a fish tank. (clarify that maximum human beings end at this) 2. understand that the gas created is heavier than air. 3.mild the candle and dip it into the fish tank the flame will bypass out. 4. Make recognize the place the line of gas is. 5. like the candle returned and lightweight it. 6. clarify that the invisible gas because of the fact it extremely is heavier than air can be able to pour like water. 7. Scoop the gas with the cup and use a funnel to go the gas so the flame will bypass out. 8. do this in different different the way you may emphasise your element. additionally you may blow up a balloon and it will end in simple terms in the past the gas line. This became an extremely cool while my 8th grade technology instructor did it. carry self belief and it would possibly be an incredible instruct.

Answer 6

http://www.chemicalfabricsandfilm.com/pdfs_researchSection/techSupport/surface.pdf
http://education.yahoo.com/reference/encyclopedia/entry/surfacet
http://www.suzy.co.nz/suzysworld/Factpage.asp?FactSheet=66
I got these sites off of google, all you have to do is search surface tension facts. then see what you get. the internet is a great place... good luck.

Answer 7

what is your project, you should have mentioned it