Answer :
Charles's Law : It is defined as the volume is directly proportional to the temperature of the gas at constant pressure and number of moles.
Mathematically,

Boiling water bath Cool bath 1 Cool bath 2
Temperature (⁰C) 99 17 2
Temperature (K)(T) 273+99=372 273+17=290 273+2=275
Volume of water 0.0 27.0 34.0
in cool flask (mL)
Volume of water= 135.8 135.8 135.8
Air in flask (mL)
Volume of air 135.8 108.8 101.8
in cool flask (V)

The graph volume versus temperature for a gas is shown below.
I believe the answer is C) there is an obvious reasoning for this all you have to do is eliminate answers that don't seem right for example, A)the plates are all moving the same direction every plate moves in different directions. B) The plates are all the same size. Well, it's really obvious that that is not true because every plate has its different shape and size. D) where two plates meet, they always move apart. If this were true, then we would never have earthquakes when plates meet earthquakes happen. so there for the answer is C)
Answer:NaF is ionic. NF3 is covalent. SiF4 is ionic. CaF2 is Ionic and NH4F is also ionic. Ionic compounds transfer electrons whereas covalent compounds share electrons hence the word "co". Also, ionic compounds are formed with metal and nonmetal. Where a covalent is with 2 nonmetals. Only ionic compounds would produce fluoride in water because ionic compounds can dissolve in water and covalent compounds cant.