HELP ME PLSSS FAST PLS

Agas can holds 2.0 gal of gasoline. what is this quantity in cubic centimeters?

If it is an isoelectronic series select true, if not select false. o2-, s2-, se2-, te2- na+, k+, rb+, cs+ n3-, p3-, as3-, sb3- ag, cd+, sn3+, sb4+ f-, cl-, br-, i- f-, ne, na+, mg2+ s2-, s, s6+

Which of the following is described by the equation h2o(s)+ heat=h2o(i) a freezing melting condensing evaporating