Suppose that for a fixed$-$pressure system with pressure of $1$ atm and temperature $300$ K $,$ a given material has two possible phases: liquid $($L$)$ and solid $($S$).$ We start the system with

$N_L=5$ moles in the liquid phase and

$N_S=4$ moles in the solid phase.

For these values of pressure and temperature,

${}_L=5{10}^{-21}J$

${}_S=9{10}^{-21}J.$

What is the equilibrium value of $N_L?$

$($a$)9$ moles

$($b$)5$ moles

$($c$)1\mathrm{.}49$ moles

$($d$)0$ moles

$($e$)4$ moles