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.
Sulphates are usually soluble in water except for Ag2SO4, BaSO4, CaSO4 and PbSO4 (lead sulphate).  Hope that helps (:  PbSO4 is sparingly soluble in water, its solubility at â¦ 298K is about 1.4E-4 mol/L, a very small value. So its not insoluble, it just has a very small solubility.ll nitrates are soluble in water. Lead, Silver, and Mercury, however, are some of the most insoluble metals. The halides of these metals are almost always considered insolubl â¦ e. 2 people found this useful.