Answer
$P = 1.02\times 10^{-16}~atm$
Work Step by Step
We can find the pressure as:
$PV = NkT$
$P = (\frac{N}{V})~(kT)$
$P = (\frac{100}{1~cm^3})(\frac{10^6~cm^3}{1~m^3})(1.38\times 10^{-23}~J/K)(7500~K)$
$P = 1.035\times 10^{-11}~Pa$
We then convert the pressure to units of atm:
$P = (1.035\times 10^{-11}~Pa)(\frac{1~atm}{1.013\times 10^5~Pa})$
$P = 1.02\times 10^{-16}~atm$
