A nucleus of an element $_{84}{X^{202}}$ emits an $\alpha-$ particle first, a $\beta-$ particle next and then a gamma photon. The final nucleus formed has an atomic number

A radioactive nucleus undergoes a series of decay according to the scheme

$A\xrightarrow{\alpha }{{A}_{1}}\xrightarrow{\beta }{{A}_{2}}\xrightarrow{\alpha }{{A}_{3}}\xrightarrow{\gamma }{{A}_{4}}$

If the mass number and atomic number of $A$ are $180$ and $72$ respectively, then what are these number for $A_4$

A nuclear reaction given by $_Z{X^A}\, \to {\,_{Z + 1}}{Y^A}{ + _{ - 1}}{e^0} + \bar p$ represents

Which of the following will have highest penetrating power

${U^{238}}$ decays into $T{h^{234}}$ by the emission of an $\alpha - $ particle. There follows a chain of further radioactive decays, either by $\alpha - $ decay or by $\beta $ - decay. Eventually a stable nuclide is reached and after that, no further radioactive decay is possible. Which of the following stable nuclides is the and product of the ${U^{238}}$ radioactive decay chain

When $_{90}T{h^{228}}$ transforms to $_{83}B{i^{212}}$, then the number of the emitted  $\alpha$- and $\alpha$- particles is, respectively