$\beta$- rays emitted by a radioactive material are
Electromagnetic radiation
The electrons orbiting around the nucleus
Charged particles emitted by nucleus
Neutral particles
A radioactive sample disintegrates via two independent decay processes having half lives $T _{1 / 2}^{(1)}$ and $T _{1 / 2}^{(2)}$ respectively. The effective half- life $T _{1 / 2}$ of the nuclei is
If $20\, gm$ of a radioactive substance due to radioactive decay reduces to $10 \,gm$ in $4 \,minutes,$ then in what time $80\, gm $ of the same substance will reduce to $10 \,gm$
Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion $5$ billion years ago. The other was created in a nuclear reactor $5$ minutes ago. The probability of decay during the next time is
The count rate of a Geiger- Muller counter for the radiation of a radioactive material of half life of $30\, minutes$ decreases to $5\,{s^{ - 1}}$ after $2\, hours.$ The initial count rate was..........${s^{ - 1}}$
A radioactive isotope has a half-life of $T$ years. How long will it take the activity to reduce to $(a)$ $3.125\% $ $(b)$ $1\% $ of its original value?