The half-life of a radioactive substance is $20\, min$. The approximate time interval $\left(t_{2}-t_{1}\right)$ between the time $t_{2},$ when $\frac{2}{3}$ of it has decayed and time $t_{1},$ when $\frac{1}{3}$ of it had decayed is (in $min$)

  • [AIIMS 2018]
  • A

    $14$

  • B

    $20$

  • C

    $28$

  • D

    $7$

Similar Questions

Match List $I$ (Wavelength range of electromagnetic spectrum) with List $II$ (Method of production of these waves) and select the correct option from the options given below the lists

List $I$ List $II$
$(1)$ $700\, nm$ to $1\,mm$ $(i)$ Vibration of atoms and molecules
$(2)$ $1\,nm$ to $400\, nm$ $(ii)$ Inner shell electrons in atoms moving from one energy level to a lower level
$(3)$ $ < 10^{-3}\,nm$ $(iii)$ Radioactive decay of the nucleus
$(4)$ $1\,mm$ to $0.1\,m$ $(iv)$ Magnetron valve

  • [JEE MAIN 2014]

In Fig. $X$ represents time and $Y$ represents activity of a radioactive sample. Then the activity of sample, varies with time according to the curve

A sample contains $16\, gm$ of a radioactive material, the half life of which is two days. After $32\, days,$ the amount of radioactive material left in the sample is

Substance $A$ has atomic mass number $16$ and half life of $1$ day. Another substance $B$ has atomic mass number $32$ and half life of $\frac{1}{2}$ day. If both $A$ and $B$ simultaneously start undergo radio activity at the same time with initial mass $320\,g$ each, how many total atoms of $A$ and $B$ combined would be left after $2$ days $.........\times 10^{24}$

  • [JEE MAIN 2023]

A radioactive element $ThA (_{84}Po^{216})$ can undergo $\alpha$ and $\beta$ are type of disintegrations with half-lives, $T_1$ and $T_2$ respectively. Then the half-life of ThA is