Which of the following will increase the strength of a sample of 90% SiO2 - 10% MgO

3 answers

what's on the list?
Quench the entire sample in water

Quench half of the sample in water

Cool the entire sample with air jets

Cool half the sample with air

Submerge the sample in a salt bath of Na2O

Submerge the sample in a salt bath of CaO
A, C & F