The volume of water in the graduated cylinder is 5.7 mL, volume increases to the value 17.3 mL when a 14.24 g of rock is dropped into it.
The increase in volume is due to the added volume of rock. Thus, volume of rock can be calculated by subtracting initial volume from the final volume as follows:

On putting the values,

For correct significant figures, volume should be in 2 significant figures.
Therefore, volume of rock will be 12 mL.
I believe that the answer is C
Flammmability is a chemical change because it changes the composition of the object. the product is very different from the rectant.
Potassium and calcium fluoride are both metals