Question

A nucleus `""_11^24Na`  emits a beta particle to change into Magnesium (Mg).

1. Write the symbolic equation for the process.
2. What are numbers 24 and 11 called?
3. What is the general name of `""_12^24Mg `with respect to `""_11^24Na`?

Answer 1

(i) In beta emission, the mass number remains unchanged and the atomic number increases by 1.

\[{}^{24}{11}\mathrm{Na} \rightarrow {}^{24}{12}\mathrm{Mg} + {}^{\;\;0}_{-1}e\]

sodium  Magnesium  Beta particle

(ii) The number 24 is the mass number of the nucleus and 11 is the  atomic number.

(iii) `""_11^24Na `and `""_12^24Mg ` are isobars, i.e., `""_12^24Mg ` is an isobar of `""_11^24Na  ` as they have same mass number (protons + neutrons) but different atomic number (protons).