What is Half Life Period?

Half Life Period is defined as the time taken for half of the reaction to be completed i.e. the time in which the concentration of a reactant is reduced to half of its original value is called Half Life Period of the reaction.
General expression for half life period of a reaction of nth order will be as follows:

For zero order, t_1/2 α [A₀]
For 1st order, t_1/2 α [A₀] ⁰
Similarly for 2nd order, t_1/2 α [A₀] ^-1 and so on
In general, for a reaction of nth order:
t_1/2 α [A₀] ^1-n
Or
t_1/2 α 1/ [A₀] ^{n- 1}