The reaction $2NO + O_2 \rightarrow 2NO_2$ is an example of which order of reaction?

Which of the following is an elementary reaction?

What is the relationship between the half-life period $(t_{1/2})$ and the initial concentration $([R]_0)$ for a reaction of order $n$?

The following mechanism has been proposed for the reaction of $NO$ with $Br_2$ to form $NOBr$:
$NO_{(g)} + Br_{2(g)} \rightleftharpoons NOBr_{2(g)}$
$NOBr_{2(g)} + NO_{(g)} \longrightarrow 2NOBr_{(g)}$
If the second step is the rate-determining step,the order of the reaction with respect to $NO_{(g)}$ is:

In a reaction,$A + B \rightarrow$ product,the rate is doubled when the concentration of $B$ is doubled,and the rate increases by a factor of $8$ when the concentrations of both the reactants $(A$ and $B)$ are doubled. The rate law for the reaction can be written as:

Velocity constant $K$ of a reaction is affected by