Inevitable manufacturing imperfections in optical fiber leads to birefringence, which is one cause of pulse broadening in fiber-optic communications. Such imperfections can be geometrical (lack of circular symmetry), due to stress applied to the optical fiber and/or due to bending of the fiber.
1. Hyaline: most common; found in the ribs, nose, trachea. Is a precursor of bone
2. Fibro: found in invertebral discs, joint capsules, and ligaments.
3. Elastic: found in the external ear, epiglottis, and larynx.
Answer:
20.3 kJ of heat is absorbed when 9.00 g of steam condenses to liquid water.
Explanation:
Heat is being consumed during vaporization and heat is being released during condensation.
To vaporize 1 mol of water, 40.66 kJ of heat is being consumed.
Molar mass of water = 18.02 g/mol
Hence, to vaporize 18.02 g of water , 40.66 kJ of heat is being consumed.
So, to vaporize 9.00 g of water, 
of heat or 20.3 kJ of heat is being consumed
As condensation is a reverse process of vaporization therefore 20.3 kJ of heat is absorbed when 9.00 g of steam condenses to liquid water.
So there are basically five types of chemical reactions which have their general formulas.
They are:
1. Combination reaction
General formula : A+B = AB
2. Decomposition reaction
General formula: AB = A+B
3. Single displacement reaction
General formula: AB+C = CB + A
4. Double displacement reaction
General formula: AB+CD = CB+AD
5. Acid-base reaction
General formula: A+B = S+W
You should check and compare with examples.
