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.
The hemihydrate (half a mole of water bound in the crystal structure of a mole of calcium sulfate) has solubility of only .24g per 100mL water (at 20 degrees C) -- this is quite poor solubility.The dihydrate has somewhat better solubility in water I believe, but still relatively low.he hemihydrate (half a mole of water bound in the crystal structure of a mole of calcium sulfate) has solubility of only .24g per 100mL water (at 20 degrees C) -- this is quite poor solubility. The dihydrate has somewhat better solubility in water I believe, but still relatively low.