Examples of index fossils. Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages).
Methyl cellulose. Methyl cellulose (or methylcellulose) is a chemical compound derived from cellulose. It is a hydrophilic white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel.
For example, ionic compounds are insoluble in hexane. It is more difficult to predict the solubility of polar molecular substances than to predict the solubility of ionic compounds and nonpolar molecular substances. Many polar molecular substances are soluble in both water and hexane.For example, ethanol is miscible with both water and hexane. The following generalization is helpful: Substances composed of small polar molecules, such as acetone and ethanol, are usually soluble in water.hen you place a non-polar molecule in a polar solvent (like oil in water) the molecules try to minimize surface contact between them. (like you and a guy with a cold on an elevator). This is actually the basis for the cells in our bodies.