In the ascending order of their tensions, water would be the first, then alcohol and finally the mineral oil.-OH would diffuse faster because its molecular mass is less than that of Water. Check out our homemade anemometer for measuring wind speed. The oil forms a layer at the surface, with the water under it. The process was simple – we used a plastic pipette to drop our liquids onto a penny, and we counted how many drops of each the penny held before the liquid spilled off the side of the penny. Demonstrate that air takes up space with a bottle, funnel, and clay – this is fun to watch! While the boys were taking a break, I did a little googling to help explain our results! We specialize in LEGO building ideas, STEM activities, and play ideas for active kids! Surface tension and interfacial tension exist when two phases are present, and the phases can be gas/oil, oil/water, or gas/water. We actually tried again with just water on another day, and got totally different results, so now I wonder if the weather affects this experiment as well. The lighter would diffuse quickly. Surface tension is a phenomenon in which the surface of a liquid, where the liquid is in contact with a gas, acts as a thin elastic sheet. Because most kinds of oil are less dense than water, most spilled oil floats on the water surface. If the boundary is between a liquid and a solid or between a liquid and a gas (air) the attractive forces are referred to as surface tension. This is a table of surface tension values for some interfaces at the indicated temperatures. The picture at the top was on a humid day, and then the photo below was a penny on a dry day. It’s also fun to drop water on a bird’s feather. I knew that the oil should have less surface tension than the water, but we had equal results – 23 drops for each. Frugal Fun for Boys and Girls is a place to find fun activities that kids will LOVE! The surface tension between gas and crude oil ranges from near zero to approximately 34 dynes/cm and is a function of pressure, temperature, and the composition of … We were only able to get 11 drops of soapy water on the penny. … Your penny shot is money :) And 27 drops - I'm very impressed. Using this method, it was obvious that water was the winner on surface tension! The surfactant we will use is dish detergent, which helps break up the surface tension between oil and water because it is amphiphilic: partly polar and partly nonpolar. This term is typically used only when the liquid surface is in contact with gas (such as the air). Without surface tension the boundary would be much more complex and more easily disrupted into a water/oil foam. The surface tension of water is an important parameter for many biological or industrial processes, and roughly a factor of 3 higher than that of nonpolar liquids such as oils, which is usually attributed to hydrogen bonding and dipolar interactions. Soapy water had the least surface tension. If the surface is between two liquids (such as water and oil), it is called "interface tension." I found a great article on the penny experiment at Teach Engineering. Our results were interesting. One thing that makes water special is its surface tension. Definitions ... •Use vegetable oil first! Several effects of surface tension can be seen with ordinary water: Surface tension is caused by the inward attraction of molecules at a boundary. Surface tension is a measure of the force acting at a boundary between two phases. soap decreases the surface tension of water to about a third, Demonstrate that air takes up space with a bottle, funnel, and clay. If the drops of water were larger than the drops of oil, then we actually had more water on our penny than we had oil. How spilled oil affects near-surface creatures depends on when and where the oil spills—those creatures might or might not even be in the area at the location and time of a spill. The purpose of our experiment was to see which liquid has the most surface tension: water, soapy water, or vegetable oil. The water molecules at the surface of a puddle of water have more attraction to each other than they do to the air molecules above them, so they create a dome shape as they try to stick together. Surface tension is the attraction that molecules in a liquid have for each other. It was a really good experiment to write about because we had to re-work our results, and because we discovered some interesting things along the way. It spreads out and is pushed across the water by wind and currents. How spilled oil affects near-surface creatures depends on when and where the oil spills—those creatures might or might not even be in the area at the location and time of a spill. I had the boys write out all of the steps of the scientific method for this experiment. Check out the Instagram page for a list of all the blog posts that have been featured on Instagram.