Half-life of a radioactive substance is $20$ minutes. Difference between points of time when it is $33\%$ disintegrated and $67\%$ disintegrated is approximately ........... $min$
Half-life of a radioactive substance is $20$ minutes. Difference between points of time when it is $33\%$ disintegrated and $67\%$ disintegrated is approximately ........... $min$
- [AIIMS 2000]
- A
$10$
- B
$20 $
- C
$30$
- D
$40 $
Similar Questions
Half life of radium is $1620$ years. How many radium nuclei decay in $5$ hours in $5\, gm$ radium? ( Atomic weight of radium $= 223$)
Half life of radium is $1620$ years. How many radium nuclei decay in $5$ hours in $5\, gm$ radium? ( Atomic weight of radium $= 223$)
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
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]
Two radioactive nuclei $P$ and $Q,$ in a given sample decay into a stable nucleus $R.$ At time $t = 0,$ number of $P$ species are $4\,\, N_0$ and that of $Q$ are $N_0$. Half-life of $P$ (for conversion to $R$) is $1$ minute where as that of $Q$ is $2$ minutes. Initially there are no nuclei of $R$ present in the sample. When number of nuclei of $P$ and $Q$ are equal, the number of nuclei of $R$ present in the sample would be
Two radioactive nuclei $P$ and $Q,$ in a given sample decay into a stable nucleus $R.$ At time $t = 0,$ number of $P$ species are $4\,\, N_0$ and that of $Q$ are $N_0$. Half-life of $P$ (for conversion to $R$) is $1$ minute where as that of $Q$ is $2$ minutes. Initially there are no nuclei of $R$ present in the sample. When number of nuclei of $P$ and $Q$ are equal, the number of nuclei of $R$ present in the sample would be
- [AIPMT 2011]
At a given instant there are $25\%$ undecayed radioactive nuclei in a same. After $10 \,sec$ the number of undecayed nuclei reduces to $6.25\%$, the mean life of the nuclei is...........$ sec$
At a given instant there are $25\%$ undecayed radioactive nuclei in a same. After $10 \,sec$ the number of undecayed nuclei reduces to $6.25\%$, the mean life of the nuclei is...........$ sec$
Deuteron is a bound state of a neutron and a proton with a binding energy $B = 2.2\, MeV$. A $\gamma $ -ray of energy $E$ is aimed at a deuteron nucleus to try to break it into a (neutron + proton) such that the $n$ and $p$ move in the direction of the incident $\gamma $ -ray. If $E = B$, show that this cannot happen. Hence calculate how much bigger than $B$ must $E$ be for such a process to happen.
Deuteron is a bound state of a neutron and a proton with a binding energy $B = 2.2\, MeV$. A $\gamma $ -ray of energy $E$ is aimed at a deuteron nucleus to try to break it into a (neutron + proton) such that the $n$ and $p$ move in the direction of the incident $\gamma $ -ray. If $E = B$, show that this cannot happen. Hence calculate how much bigger than $B$ must $E$ be for such a process to happen.