The pair,in which ions are isoelectronic with $Al^{3+}$ is ..... .

Which of the following is not isoelectronic with $O^{2-}$?

The isobars are atoms with the same number of

Match the isotopes in List $I$ with the number of neutrons in List $II$.

$(A)$. $^{24}_{12}Mg$	$(I)$. $5$
$(B)$. $^{27}_{13}Al$	$(II)$. $12$
$(C)$. $^{9}_{4}Be$	$(III)$. $6$
$(D)$. $^{12}_{6}C$	$(IV)$. $14$

The chlorine atom differs from the chloride ion in the number of:

Write the complete symbol for the atom with the given atomic number $(Z)$ and atomic mass $(A)$:
$(i)$ $\quad Z=17, A=35$
$(ii)$ $\quad Z=92, A=233$
$(iii)$ $\quad Z=4, A=9$