In a metal ceramic crown for a FPD the function of tin, indium which are readily oxidized minor constituents is to________________?

In a metal ceramic crown for a FPD the function of tin, indium which are readily oxidized minor constituents is to________________?

A. Improve bonding
B. Decrease porosity
C. They react with the porcelain opaque layer, which masks the metal
D. Improves the thermal expansion between the metal and porcelain

Silica sol__________________?

Silica sol__________________?

A. Is applied to the walls of the investment to produce hygroscopic expansion
B. Increase the strength and the setting expansion of the phosphate-bonded investment
C. Acts as a retarder in the silica bonded investments
D. Acts as a refractory in the Silica bonded investments