Posted Date: 10/08/2020
COPPERAS COVE, TX (October 7, 2020)—Copperas Cove Junior High student Serena Streeto slowly dipped a piece of cardstock into a mixture of water, vegetable oil and food coloring through a method called hydro-dipping. She gasped when she saw the results.
“I didn't know oil could stick color to paper,” Streeto said. “It was cool and fun. I am going to teach my sister and my family how to do it.”
The young scientists in STEM labs teacher, Chelsie Raysor’s class were studying and calculating density of substances. They applied their knowledge of measuring both mass and volume to determine the densities of both regular objects and irregular objects. Their grand finale each day has been a Science Art project in which they combine a mixture of oil and food dye, and layer it on a small volume of water to marble a piece of cardstock
“Prior to the art activity, the students reviewed the components of density calculation in isolation. They used pure math to calculate the density of a regularly shaped object, a rectangular prism with given dimensions, to determine that because its density comes out to .075, it would float,” Raysor said.
For these sixth graders new to junior high, this connection is their next level beyond the early elementary Texas Essential Knowledge and Skills where they classify objects that sink or float and are able to begin using math to determine if objects will sink or float without dropping them in water.
“The art project gives them the density of vegetable oil, which is less dense than water, and tells us it will float on the layer of water prepared in their trays,” Raysor said. “By combining the food dye that would normally disperse into the water and color it with oil, the color remains floating atop such that the students are able to lay their sheet of cardstock onto the coloring and obtain the marbled effect.”
Many of the students shared real world connections having seen similar ideas on YouTube for marbling nail polish, hydro-dipping used on Yeti cups and other substances, understanding that density is the result of the final product.
“This lab was chosen as a real-life connection for students to see why some substances float understanding the mass they contain is spread out over enough volume to allow it, and how to calculate if a substance would sink or float without having to revert to their elementary experiments of dropping them into water to find out,” Raysor said.
For their next assignment, students will measure an irregular object, a lump of clay, using a triple beam balance to determine its mass. They will use displacement and a graduated cylinder to measure the volume of the clay. Once students obtain these two measurements, they will calculate the density of their clay to determine that it is denser than water and will sink as they determined with their cylindrical view.