Ramendra C Mukerjee Solutions for Chapter: Atomic Structure and Radioactivity, Exercise 2: Objective Problems

Which of the following statements is/are correct?

A radioactive isotope having a half-life of $3$ days was received after $12$ days. It was found that there were $3 \mathrm{g}$ of the isotope in the container. The initial weight of the isotope when packed was

If ${\mathrm{N}}_0$ is considered as the initial number of nuclei, number of nuclei remaining undecayed at the end of ${\mathrm{n}}^{\text{th}}$ half-life is

A radioactive substance is decaying with ${\mathrm{t}}_{\frac{1}{2}}=30 \mathrm{days}$. On being separated into two fractions, one of the fractions, immediately after separation, decays with ${\mathrm{t}}_{\frac{1}{2}}=2 \mathrm{days}$. The other fraction, immediately after separation, would show:

A radioactive substance has a constant activity of $2000$ disintegrations per minute. The material is separated into two fractions, one of which has an initial activity of $1000$ disintegrations per minute while the other fraction decays with ${\mathrm{t}}_{\frac{1}{2}}=24 \mathrm{hours}$. The total activity in both samples after $48 \mathrm{hours}$ of separation is:

The orbital angular momentum $\left(\mathrm{L}\right)$ of an electron in $2\mathrm{s}$ orbital is

For a $\mathrm{d}-$electron, the orbital angular momentum is

${}_{13}{}^{27}\mathrm{Al}$ is a stable isotope. ${}_{13}{}^{29}\mathrm{Al}$ is expected to disintegrate by