221. Which of the following statement is correct regarding chemical setting of condensation silicone?

a)   Polymerization occurs with repeated elimination of small molecules

b)   Polymerization occurs with elimination of  single byproduct

c)   It occurs by repeated condensation of molecules of monomers

d)   Condensation does not occur at all   ( AIPG 2010  ) (Repeat: AIPG 2007)    \

220.Shoe leather survey was conducted in

a.Japan
b.USA
c.France
d.Germany

Ans:b.USA

219.The total pore volume of dark zone is

a.2-4%
b.20-40%
c.5-10%
d.0.1-1%


Ans:a.2-4%


Expalanation:Ref sturdevant 4th ed /pg 95