According to Clausius-Clayperon equation,

is the vapor pressure at boiling point = 760 torr
is the vapor pressure at T_{2} =638.43 torr
Temperature
Δ
Plugging in the values, we get

ln

Therefore, the boiling point of octane = 389 K - 273 = 
Neon. Neon is a gas that glows red-ish when electricity flows through it in neon signs etc.
It shall be A.<span>Oppositely charged ions attract</span>
It means it is an ion. It has lost two protons making it a positive ion.