The relationship between the half life period and the rate constant is, \\\\(\\displaystyle t_{1/2} = \\frac {0.693}{k}\\\\).(i) \\\\(\\displaystyle t_{1/2} = \\frac {0.693}{200} = 3.465 \ imes 10^{-3} \\: s\\\\)(ii) \\\\(\\displaystyle t_{1/2} = \\frac {0.693}{2} = 0.3465 \\: mins\\\\)(iii) \\\\(\\displaystyle t_{1/2} = \\frac {0.693}{4} = 0.1732 \\: years\\\\)