Nitrous oxide $(N_{2}O)$ is used as an anesthetic $($laughing gas$)$ and in aerosol cans to produce whipped cream. It is also a potent greenhouse gas. The decomposition of $N_{2}O$ is first order. It decomposes slowly to $N_2$ and $O_2$ :

$2N_{2}O(g)longrightarrow2N_2(g)+O_2(g)$

$3$rd attempt

See Periodic Table

See Hir

How many half$-$lives will it take for the concentration of the $N_{2}O$ to reach $3\%$ of its original concentration?