The half$-$life for the $($first$-$order$)$ radioactive decay of ${?}^{14}C$ is $5730y.$ An archaeological sample contained wood that had only $72$ per cent of the ${?}^{14}C$ found in living trees. What is its age?

Nitrogen gas adsorbed on charcoal to the extent of $0\mathrm{.}921c{m}^3{g}^{-1}$ at $490$kPa and $190K,$ but at $250K$ the same amount of adsorption was achieved only when the pressure was increased to $3\mathrm{.}2$ MPa. What is the enthalpy of adsorption of nitrogen on charcoal?

The following data are for the chemisorption of hydrogen on copper powder at $25C.$ Confirm that they fit the Langmuir isotherm at low coverages. Then find the value of $K$ for the adsorption equilibrium and the adsorption volume corresponding to complete coverage.

$\backslash$table$[[\frac{p}{P}a,25,129,253,540],[\frac{V}{c}{m}^3,0\mathrm{.}042,0\mathrm{.}163,0\mathrm{.}221,0\mathrm{.}321]]$