Nuclear Physics & Radioactivity

The atomic nucleus is composed of ...

An alpha particle is identical to ...

In negative beta decay, the atomic number of the nucleus ...

Gamma radiation is ...

Half-life is the time required for a radioactive substance to ...

One atomic mass unit (u) is equivalent to an energy of ...

A radioactive substance of mass $20\text{g}$ has a half-life of $5\text{years}$. After $15\text{years}$, the remaining mass is ...

The half-life of an isotope is $10\text{days}$. After $30\text{days}$, the fraction that has not decayed is ...

The relationship between mass and energy is expressed by the equation ...

The decay of ${}_{92}^{238}\text{U}$ into ${}_{90}^{234}\text{Th}$ occurs through the emission of ...

The number of remaining nuclei is $N=N_0{\left(\frac{1}{2}\right)}^{t/T}$. If $N_0=80$ and $t=3T$, the value of $N$ is ...

In positive beta decay, the nucleus ...

The activity of a radioactive substance after two half-lives becomes ...

Nuclear binding energy is ...

The mass defect of a nucleus is $0.03\text{u}$. If $1\text{u}=931\text{MeV}$, its binding energy is ...

A nucleus with a mass defect of $0.2\text{u}$ has $4$ nucleons. Its binding energy per nucleon is ... $(1\text{u}=931\text{MeV})$

The isotope ${}^{14}\text{C}$ has a half-life of $5,730\text{years}$. A fossil has $25\%$ of its initial activity. Its age is about ...

A radioactive substance is left with $\frac{1}{16}$ of its original amount. It has decayed for ... half-lives.

The decay constant $\lambda$ is related to the half-life $T_{1/2}$ by ...

In a nuclear reaction, the mass decreases by $2\times 10^{-3}\text{kg}$. The energy released is ... $(c=3\times 10^8\text{m/s})$