Question

The radioactive atom $_{{\text{84}}}^{{\text{210}}}{\text{Po}}$ decays by alpha emission. How would you write an equation showing the decay?

Answer 1

Hint:To answer this question what mass number and proton number is. What alpha particles are and how the mass number and proton number change when alpha particle emits. A radioactive decay equation shows the decaying radioactive nuclei and newly formed radioactive nuclei and the particles that emit.

Complete answer:
The atomic number is the number of protons present in the nucleus of an atom. Every atom has a unique atomic number.
The atomic representation is as follows:
\[_{\text{Z}}^{\text{A}}{\text{X}}\]
\[{\text{X}}\]is the symbol of the atom.
\[{\text{Z}}\] is the atomic number of proton number.
\[{\text{A}}\]is the atomic mass.
The helium nucleus is known as alpha particles. The representation of the helium nucleus is as follows:
$_{\text{2}}^{\text{4}}{\text{He}}$
So, when an alpha particle emits from a radioactive nucleus. The atomic number of that nucleus decreases by two and the mass number of that nucleus decreases by four.
The equation for the emission of an alpha particle form polonium is shown as follows:
$_{{\text{84}}}^{{\text{210}}}{\text{Po}}\, \to \,\,_{82}^{206}{\text{Pb}}\,\, + \,\,_{\text{2}}^{\text{4}}{\text{He}}\,$
We know that lead has an atomic number $82$ .
So, by the emission of alpha particle from $_{{\text{84}}}^{{\text{210}}}{\text{Po}}$, the $_{82}^{206}{\text{Pb}}$ forms.
Therefore, the equation showing the decay of $_{{\text{84}}}^{{\text{210}}}{\text{Po}}$ is, $_{{\text{84}}}^{{\text{210}}}{\text{Po}}\, \to \,\,_{82}^{206}{\text{Pb}}\,\, + \,\,_{\text{2}}^{\text{4}}{\text{He}}\,$

Note: The alpha particles are represented by $_{\text{2}}^{\text{4}}{\alpha }$. The radioactive decay follows the law of conservation of mass. The atomic number is the number of the proton. The mass number is the sum of the number of protons and the number of neutrons. During the radioactive decay, the heavy radioactive element breaks into smaller radioactive nuclei elements and emits alpha, beta particles, electrons or gamma radiation.