Cup of Lava

I.Introduction
Salt, also known as common salt, table salt, rock salt, or halite, is an ionic compound with the formula NaCl (sodium+chloride). Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms. As the major ingredient in edible salt, it is commonly used as a condiment and food preservative. Because of its importance to survival, salt has often been considered a valuable commodity during human history. However, as salt consumption has increased during modern times, scientists have become aware of the health risks associated with high salt intake, including high blood pressure in sensitive individuals. Therefore, some health authorities have recommended limitations of dietary sodium, although others state the risk is minimal for typical western diets.

Oil is any neutral chemical substance that is a viscous liquid at ambient temperatures, is immiscible with water but soluble in alcohols or ethers. Oils have a high carbon and hydrogen content and are usually flammable and slippery (nonpolar). Oils may be animal, vegetable, or petrochemical in origin, volatile or non-volatile. Oil is a fossil fuel. Most of the oil extracted today has been formed from prehistoric organisms whose remains settled at the bottoms of oceans and lakes millions of years ago. As layers of sediment covered them, the pressure on them increased which in turn increased the temperature. This process changed their chemical composition, eventually transforming them into oil.

II.Materials & Methods
Materials
The materials needed for this experiment are a tall clear drinking glass, 1/4 cup olive/vegetable oil, 1 or more teaspoon of salt, tap water, Food coloring (red, green, blue, and any other color you like), eye dropper(optional if your food coloring is not in a dropper).

Procedures
To start the activity, fill the glass about 2/3 full of water do not fill it all the way so that there is enough room left for the oil. Add a few drops of food coloring (any color that you have or you like). Slowly pour the vegetable oil into the glass. Add several drops of food coloring. Then sprinkle salt on top of the oil. Watch blobs of lava move up and down in your glass! If you liked that, add another teaspoon of salt to keep the effect going. III.Conclusions

Density is the measurement of mass and volume. When a water (higher density) is mixed with oil (lower density), the oil floats on top. This is because oil is less dense than water. Salt has a density that is higher than either oil or water, so when salt is added, a bubble of oil is formed around it and it sinks to the bottom of the glass, carrying some oil with it. Because the salt and the oil put together are denser than the water. As the salt begins to dissolve in the water, the oil is released and floats back up to the top of the glass, because it is less dense than the water again. The oil and water didn’t mix because they have different polarities. Water has a charge (like a magnet) that attracts other substances. Oil on the other hand does not have a charge. That is why when going through water oil looks like little bubbles but doesn’t mix with the water.