Need help on 12,13,14 ONLY IF YOU ARE POSITIVE!!

Which element forms an ionic bond with flourine? 1) fluorine 2) carbon 3) potassium 4) oxygen

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Apropane torch is lit inside a hot air balloon during preflight preparations to inflate the balloon. which condition of the gas remains constant